Ygtjki

Oh man, where does one begin...

I am half-way in to my second postdoc at what I consider to be the best research facility in Northern Europe in my field. So take my advice as such, although where you work does not say so much about you, as one might think.

How do I gain back my faith in my PhD degree?

Short answer: you don't, as long as you are in status quo. If something changes by an act of serendipity, maybe you do..

Longer answer: you might regain some faith, by reframing your reference point. In other words, change your expectations and your feelings might change as well.

Regarding the questions the student asked you:

1. If optimizing your overall income is a primary concern, don't bother with a PhD. Yes, there are cases where having a phd might pay off by making a high-paid job available, but cumulative work experience, raises as well as the confidence and training you get on job will likely end up as a bigger plus.

... wish to be financially independent and have an early retirement. Can doing a PhD for five years offer this reality?

There is certainly no reason to panic if financial independency is what you are striving towards, though. I have been financially independent from my family/loans the entirety of my graduate studies, and even managed to save enough money to get a mortgage loan to buy myself an apartment (small but more than decent) while I was a PhD student.

That might be more of a statement of which country you live in (e.g. Sweden vs USA) or which city you want to do pursue graduate studies (e.g. San Francisco vs San Diego). The point is that you do make a living, you are not an undergrad anymore.

Don't even get started with pension subject, that stuff is too complicated. Practically unless you are making a stupendous salary or some wicked investment decisions there is no guaranteed early and relaxed retirement. As populations get older on average, and indirectly their costs to the society increase, the pension systems will have to undergo a significant restructuring, and I for one am expecting that to create some very heated debates and go down not so easily.

Bottomline: Do a PhD if the subject interests you deeply, or if you think you will be gaining a skill that is highly valued in industry. I am working with bioinformatics, and if I want to get a job in this field, without a PhD you are not really respected. I have some friends that have done PhDs in economics, which were highly valued and allowed them to land jobs they would have otherwise. That may not translate to every field however.

2. Doing a PhD is not an education that prepares you for a profession. It's an academic degree not a professional one. You need to keep that in mind. Actually, write it on a post-it, put on your mirror at home and repeat it to yourself everyday. Twice, if you can, in the morning and evening when you brush your teeth...

It's so easy to lose track of that insight. Doing a PhD is education to become an academic, to think critically, to be able to read and teach (to some degree at least). You will get to be a better critique of others' work and your own. You will get training on reading and writing. You will most likely face the boundaries of your intellectual capabilities. But no it does not directly imply you will be better at a job, unless that job is specifically related to the things I mentioned above.

Do you think your degree has prepared you to be competent in these areas?

No, a graduate degree has not prepared me to be a competent coder, the one skill that would make transition from academia to industry so much more smoother.

No, it shouldn't either. That's why there are certificate programs, and bootcamps, Coursera and Khan Academy, and software carpentry etc etc.

However, did you stop to consider that doing a PhD might have you working on an actual problem, to which you get to design a novel algorithm to solve that problem, or to improve the solution? Or maybe a new protocol for networking/encryption etc? Having some specialized experience might make you an indispensable profile for a company looking for expertise in that field. But no by default, graduate studies do not make you a better professional.

3. Re: relevance

How do you know that your model can be used by actual people, like the products people develop in industry?

In most cases, you don't! At least not for sure... You can look at citations of your papers, although even that can be misleading as people cite other papers for many different reasons. I actually asked a question somewhat related to this a while back...

In some, rare, cases you might end up doing something that changes the landscape of the field; like writing a software that becomes the de facto gold standard for a particular type of analysis. You might come up with a technique or a protocol that is used by others. Or you might even stumble on some key result, by sheer luck.

More likely, you will provide incremental additions of knowledge into an ocean, most of which will go unnoticed, at least initially. If that bothers you, that is OK. It bothers me too, and I do consider my position in academia as well. But that should not cause you any despair. It only shows that you want to be proud of your work and get the acknowledgement you deserve. Unfortunately we don't always get what we want.

4. Re:Comparing yourself to the others especially on social media

While my peers on instagram or facebook are traveling all around the world, visiting new places...

Stop! Social media is literally designed to create that feeling. At the end of the day, you never know who goes home to cry about their day, no matter how amazing their Instagram photos may look, or how much "fun" they are having wherever they may be.

For many people their life online, or at least they portray their life online, has become their identity. There are many people who have analyzed this in great detail. I especially like this article (go ahead and listen to the talk in its entirety). Also read about online influencers (here's a starting point).

Edit: As @FrankHopkins pointed out in the comments, doing a PhD might actually take you to many exciting places for conferences or courses. I have been to a number of really cool places, most of which I would either not bother traveling on my own or would be able to afford at the time :)

Overall my answer(s) might appear very dystopian. But I would rather say realistic, and in any case, they are based on my experience.

I'd like to wrap it up on a positive tone, with hopefully concrete steps to help you find your way around, because ultimately, nobody can tell you if you have taken the right decision.

Here are some concrete steps I can suggest for you to feel a bit better:

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  Get a mentor! Someone at least 10 years your senior and ideally someone who has a life story that resembles your own. Of course finding a good match might be tricky but check whether or not there is a mentorship program provided by your university/faculty/student council etc.

  
  
  

  Listen to that person's story, but make sure you don't fall into tutor-student relationship. How did s/he take the critical decisions in his/her life? What was valuable to them at that time, and how did that turn out later? How does the person define success?

  
  



• Speaking of success, try to think real hard about what you define success to be. It's great to make lots of money, or have an h-index in the 100s but it's really not the whole picture. You might end up working yourself to the bone and still not be happy/successful enough. As a rule of thumb, I'd recommend avoiding taking anything quantifiable as a measure of success because anything that goes to n also goes to n+1.




• Don't let others dictate your mindset, whether they are your peers or seniors. There is a lot of "fake it 'till you make it" out there.




• Try to see where you make/made a difference. That could be helping a peer solve their problem, going to a meeting instead of your boss so that he can go take his/her sick kid from daycare. That could be helping a student in a lab, or writing to a fellow academic on the other side of the world, to help him/her sort out the mess that is a life in academia. ;)

Hope it helps!

Welcome to the real world!

My read of your question is, your student is asking questions that you didn't think of before you started your PhD. In other words, you started your PhD without really thinking about why you're doing it. This is of course less than ideal - I firmly believe you should've thought about these questions before commencing the PhD - but that's in the past now, and figuring out what to do next is more important.

So now what? I recommend first to stop worrying about "gaining back faith" in your PhD. This wording makes it sound like you want to return to your old state where you just go about your PhD blissfully unaware of what happens after. Abandon this notion because after you graduate you are going to have to face the same questions. In other words, stop thinking about the PhD as though it is sacrosanct. You don't have to complete it! If you get less out of the PhD than the effort you put in to acquire it, you can (and perhaps should) leave! There is nothing wrong with leaving - this culture is prevalent in academia but you should still not feel obliged to stay.

Next, figure out why you're doing the PhD now. Better late than never. For example,

I had really no answer to this question, as I am in constant doubts myself over the rising opportunity cost of doing a PhD. There is a part of me that beckons me to leave academia immediately. It tells me that I could do so much better, be more free only if I had made the choice after I graduated with my Bachelors. Only if I knew how little I would be paid compared to my peers.

It's good that you're thinking about this now, but you still can't make an informed decision because you don't have the facts. You need to answer questions such as:

• Is money all that important to you? Of course nobody can do without money, but if you're the kind of person for whom a $500k annual salary means a lot more than $100k/year, even though $100k/year is more than enough to live comfortably, then you want to figure that out now because it indicates you are on the wrong career path. It doesn't mean you should quit, but it does mean you'll be somewhat miserable the rest of your PhD knowing there's something "out there" that you want and can't have.


• If the answer to the above is yes, then just how much money are you missing out on? How much are you being paid now, and how much can you earn if you moved to industry? This is again something to find out. Ask your peers in industry, perhaps other undergraduates you studied with.


• If the answer to the above is no, then you know you can likely earn more elsewhere but you believe that the joys of academia more than compensate the monetary difference. In this case your financial situation isn't something to worry about (as long as you earn enough to get by) and you can put this concern out of your mind.

In conjunction with this I recommend checking out your local jobs portal for what positions you can get if you leave academia now. See if you like the jobs, see if you have the skills, see how much they pay.

I cannot say yes to this question either. I do use programming every now and then, but I am in no way comparable to a person who works solely in this field. It does seem that programming skill seems to be the only skill that employers value, a litmus or IQ test for a world of graduate students with questionable credentials. Even newly minted PhDs are directly sent to software developments, albeit more specialized. No, a graduate degree has not prepared me to be a competent coder, the one skill that would make transition from academia to industry so much more smoother.

This is another tough question that should be answered sooner rather than later. What exactly are you trying to learn? What skills do you acquire in the PhD that makes you more employable than a random MIT undergraduate with a BS degree? Figure it out because otherwise you're going to be in for a rude shock when you graduate.

If you've discovered that to succeed in industry the most important thing is to be a "competent coder", then you should absolutely focus your attention on getting as much coding experience as possible. Direct your PhD towards that. Choose a research direction that involves heavy coding. Write using different languages if you can.

Alternatively, if you're completely uninterested in industry, you can continue doing what you're doing. This commits you to the academic career path, with all its challenges and struggles. Are you game to compete against all the other PhD students out there looking for postdocs and tenure-track positions? Again this is something only you can answer. Think carefully before you answer because you'll feel truly miserable if you say yes, then discover five years in the future that the academic path isn't for you (and vice versa if you say no).

(Similar points apply to the rest of the questions you mention. Get a clear idea of what you want, and what you're missing out on if you stay in academia.)

Finally, after having amassed the facts, then you can decide what to do next. The factors involved in this decision are complex, and again only you can make the choice. You could, for example, decide that since 1) you're already 3 years into a 5-year program and 2) there are interesting jobs that require a PhD in your area, investing the two remaining years is worth it. Or maybe you could decide that it isn't worth it, in which case you can start looking for a job now and quit when you get one. Or maybe you could decide that yes, you can have a better-paying career if you quit, but you don't care about the money and would rather work on blue skies problems. Et cetera.

Good luck. Whatever you choose, it's a major life decision.

Let me give you a perspective from someone who made the opposite choice.

I was a stellar undergrad in a top 10 engineering school, got perfect grades. I took a bunch of extra stuff across many departments just because I was curious and knew I'd never get an other chance to learn things like chemistry so quickly and rigorously in a guided environment. I bounced around a few labs but always came to the conclusion that the research wasn't going to be worth as much as I'd like and moved on to the next exciting thing. I was a CS TA with great programming skills and went and got one of those sexy internships at a Big 5 software company. But I realized "the real world" I'd been told to be so scared of was a cake walk. At the Institute I worked 60-70 hour weeks at least, every week. In industry all my smartest coworkers, even the full-timers were using 30% of their intellectual capacity. It was an easy, well-paid life, but they ultimately just kept the system running and didn't often have chances to be inventive.

So I applied to grad programs at the few universities I considered to be a touch better than mine, but without published work I didn't get in to any. Ended up back at my same institution pursuing a Master's in my same discipline (Electrical Engineering), because the department was happy to give one of their best students a tuition waiver if he would TA for them. Got interested in Tissue Engineering, believing it to be the most important revolutionary technology of our age, and got in to a bioengineering PhD program. They used to pass around a list of projects new students could get involved in, just something compiled from all the PIs. I was excited and did the legwork running around talking to many of them, but their work was very much about low-level experimentation, growth factors, and live animal studies. The PhD would take 6-7 years, and I wouldn't be able to study the broader signaling/abstracted 'library' of cellular commands that I was interested in. The second year I saw the list, I went through crossing out thing after thing, now having enough knowledge to say "That will never work; that's ridiculous; we don't have nearly enough knowledge as a community to be able to succeed at this yet."

Jaded again, recognizing that a tax-break-friendly-science-antagonistic administration would be in control of government, and still carrying a significant amount of student debt, I decided to take the EE MS and look for jobs. I'd found an ever deeper affinity for the math underlying controls, signal processing, and machine learning in those couple years, and I knew I hated vanilla software engineering, but still going up to companies and hearing "Well, with your experience you could probably do any of these things. So what do you want?" was a daunting question. I settled on AI-related software and did the coding interview circuit. In the end a defense company offered me a job in a new research division. But the VP who was pushing that got forced out, and the building never got built, and I ended up bounced around to a different site (which I was okay with) working on an ML-related project.

I loved it at first, got to build a few neat things and explore, and I was well-paid. But not all was roses. I discovered that people liked to look at the org chart to see who was right instead of valuing ideas. Certain bad actors craved control and didn't appreciate my products upstaging theirs. I'm a strong personality who stands up to crazy when he sees it, and my immediate superiors didn't believe in conflict, so it became an ugly cold war. A wise lead several layers up eventually got involved, saw I was right to take a stand on certain things, and moved me to a different program, where I still get a chance to read papers and do academic things and be the "AI guru". I've watched the team I came from continue to devolve as more of my coworkers run up against the same problems and leave (9 so far out of a team of 3 in a <2 year span) while management refuses to admit their mistake and remove bad actors' authority.

I love my current group. They're good people, brilliant people, who work very well as a team. They're from diverse industries with complementary strengths, and they've been through a lot together. But they're jaded too! After exciting meetings with other smart groups across the company, they express pessimism that leadership will actually be able to knit efforts together. Time will tell whether that's justified and whether I'll feel the same.

I don't have to work that hard, but I'm not just keeping a system going. I'm designing, inventing, exploring. I've gotten in to skiing in the last year even though I live nowhere near mountains, because I have the time and money to go. I've been out of debt a while and am actually investing.

But I'm still dissatisfied. I worry that I lack the academic credentials (a body of published papers and a PhD) to really pursue the kinds of jobs I want later in my career. I feel like I'm left behind by an academia that moves apace. I don't have mentorship from real academics who are way smarter than I am. The climate is too hot. I'm not in a big city, and there are lots of engineers here, so my romantic prospects are limited by demographics--something that eats at my mind since the relationship I had in grad school fell apart, a particularly prolonged, painful process that took me a long time to understand and stop blaming myself for. (She still blames me for all her issues. Not healthy.) These days I've been getting in shape, reading more books, and trying to get back to a mental place where I could do a convincing round of coding interviews. I still want to go back to grad school, but I need to be positive the project I'll be working on is a good one in a good lab with good coworkers and a PI who won't abuse me, and I worry there's no way to get the letters of recommendation I would need to break in to such an environment.

The moral of the story is you will always question yourself. I and my brilliant CS friends who went and got jobs at Big 5 or elsewhere are doing work that's really no more meaningful than the arcane work you're doing. Sure, we as a society have decided we want the Systems to keep working or work better and are willing to throw money at the problem. But even if as a whole that's meaningful, a worker-bee's role is really small, and our work may never even see the light of day, just like how the body of scientific work is meaningful, yet your role is really small, and maybe no one will read your papers. People are rarely given the chance to have or are fortunate enough to stumble in to those eureka moments that really make a difference. That's a heartbreaking reality, but we soldier on anyway, because to not do so would be giving up, because we want to be better people, because there is a chance we can make a difference, because "it did not really matter what we expected from life, but rather what life expected from us." It's healthy to question yourself, even to become a little jaded, because it makes you wiser and keeps you on a path you actually think might go somewhere. We'd all rather you and the other bees be on those paths than ones you think are pointless and stand no chance of benefiting us, but we trust your hive-mind to make those decisions, and we'll accept long- as well as short-term benefits. Not all bees need to explore the same territory.

My advice is to excel for the 2 more years it takes to finish your PhD and be proud of what you've done, not because it's great, but because it made you intrinsically better. Sure, you've given up a lot of money, but a PhD carries respect with it because people know you made that sacrifice and walked through fire to get it, and that makes you tough, worthy of the really fulfilling inventive jobs out in the wider world. Instead of being like me, the most academic guy in a room with no others or the least academic guy in a room full of PhDs, you can belong. But also ask yourself the big questions: "What makes me happy?", "What do I want to do with my life?", "Who do I want to spend life with?", and don't neglect the answers no matter how busy you are, because otherwise you'll wake up and have a Catastrophe of Success moment when the pressure is gone. It happened to me after being so institutionalized for so long. It happens to everyone.

Here's my story. I hope it can be helpful.

My first few years in a STEM PhD program at a top-tier research university in the US were tough. I had breezed through college but struggled in grad school and felt the canonical imposter syndrome. I earned the MS when I passed the Qualifying Exams, but I had trouble settling into any particular research group or project. Like you, I wanted to do research that would improves lives around the world, but felt seriously disillusioned with the perception that most projects were doing little more than filling library shelves and advancing the reputations of the most ambitious and cut-throat careerist academics.

At one point I took leave for a term to figure things out. By this time I was married with two children. I came across Lee Smolin's book The Trouble With Physics, which opened my eyes to the serious sociological problems in STEM in general and physics in particular, but also reawakened my desire to pursue excellence in research. I spent a year and a half with a group doing research in how my discipline is taught to undergraduates, and that was very enjoyable for me.

After six years in the PhD program, and at a point where I was basically ABD, one night I looked at my wife and told her I thought it was time to walk away from the program and move to my home state. That's exactly what we did.

I had all sorts of friends and acquaintances telling me what a mistake I was making, and how much I would regret not finishing. I came under quite a bit of pressure that I didn't quite expect. But that gut feeling would not quit. It was almost a physical insistence that I no longer be there.

So we left. I got a job in my home state teaching my discipline, and eventually I made my way into semiconductors and later software development. Although there have been hard times and difficult decisions, careful consideration and honest thinking has inevitably served me well and brought me to a better spot time after time.

It's been almost a decade since I walked away from my PhD, and I can say honestly that not once have I regretted it. In fact I'm doing better than I have at any time in my life in various facets: financially, emotionally, and the degree to which I enjoy my work and feel that I am making a positive difference. I am content.

I also continue to come up with research ideas that I trust will have their time.

I would advise anyone in your spot to get somewhere quiet and carefully think about the situation and your deepest feelings about it. Whatever the nature of intuition, it will come and it is a trustworthy and reliable guide to what one should do next.

Whether it's renewed faith in your PhD or the space to allow yourself to move on, you'll find what you need, and I encourage you to trust that intuition.

All the best.

As to software development, I was a Ph.D. in EE (Signal processing using MATLAB to support research). Today, I am a professional programmer, working mostly with SQL, XML, classic-asp, asp.net, and Visual Studio. {This is called 3-stack development, or N-stack development, sometimes web development). In between, I did real-time firmware and C/C++/C# [even some assembly-language programming] and an occasional MATLAB job/project/task.

One can always learn programming if one has the desire and the time.

If you can think of a way to combine it with your research so much the better.

Even asking if your University has a website where you may post results and coding your own HTML and so forth can be good.

As for the long-term part, if you have begun the journey, I advise finishing it, but of course, that is just my opinion.

First, your reflection triggered by the undergrad's questions is in my view wide-spread among PhD students. I'd be inclined to say that far more than half run into such questions. I went through such thoughts by myself and have to say that there is unfortunately no easy answer, not at all. You basically have to decide on your own how to view and create your path, one way is to try to make the best out of what is there.

Second, I agree much with the 4 sub-answers of @posdef, adding to 1. and 2. my experience from two of my job interviews in industry: I was asked how I plan to compensate for the lack of professional experience caused by doing my PhD in computer science and how I plan to compete with usually experienced practitioners of my age that spent their postgrad work life in industry? I had a hard time in answering their question.

Point 3. is very difficult: You may have to convince yourself of your results, particularly, when nobody out there cares. It also depends on your own vision. If you don't have one, you can create one. Of course, it gets easier the more feedback you get, and by feedback I mean any kind of feedback. Negative feedback has proven most valuable to me as it helps to learn much much faster.

Regarding social media (4.), I have recently finished Jaron Lanier's book and conclude it to be a very nice guide to how to view social media. I still use it but with a drastically changed view. :)

My take-away as a computer scientist (!): a PhD in computer science by no means leads to great advantages for pursuing a career in industry, although it is surprisingly often seen primarily that way! However, as @posdef points out, it is a necessity in the training for a scientific career. And I view it only as such.

Short life story that parallels the questions:

Q1. I wish to go to graduate school, but I also fear that I will miss out opportunities to make hundreds of thousands of dollar per year working in industry. I also wish to be financially independent and have an early retirement. Can doing a PhD for five years offer this reality?

A1. Sort of. Looking back, I was an okay grad in physics - took some time for a startup, but finished PhD, found my spouse along the way - the reality of post-doc was that life wasn't going to be real productive financially. Applied to small colleges to teach, and got some very lovely rejection letters from a few Chairs that urged me to try again. I had some experiences running the official campus tutoring for undergrad physics for the university which seemed to help, but not put me over the edge. Anyhow, I quit pure academics and worked in a large scale academic simulation lab working on bleeding edge code that it productized and that is now widely used and considered a benchmark in the field. Took that experience got an MBA and shortly after was making low six figures and as a consulting partner ended up much higher. Not retired, but switched to startups and other paths recently. A lot more fun than the grid of consulting.

Q2. Programming and software development are highly valued skills in industry. Almost all jobs nowadays requires some form of it. Do you think your degree has prepared you to be competent in these areas?

Not directly. I was always programming as a child and still program today. I ended up doing a mix of hobby programming, research-academic programming, production programming, large systems programming along the way. I feel like a competent-but-uninspired programmer. I did mostly self-education and then demonstration through tangible projects over the years. I was lucky to have coworkers who were in our CS department in grad school and later and learned a lot from them. As a mgmt consultant, did not do any programming for the job but it helped me work with SW and SaaS companies on their ops and strategy. Today, in my current path - I'm again semi-self taught in machine learning / AI / CV - and learning more all the time. Its fun, but I still hate the act of programming. However, Physics was good background.

Q3. Do you believe in the theory and methodology you are developing? How do you know that your model can be used by actual people, like the products people develop in industry?

Yes, but No, but then later Yes. As a college student, I worked on product code for my startup. In academics, my code worked fine and was performant, but was barely readable academic codes, not very practical in real life, but I learned a lot about simulation, numerical methods, and high performance computing along the way. In the simulation lab, our code was used widely for large scale and nearly-production quality work - it was at the time very modern, distributed computing, OO design using a clever mix of C++ and Python - and is still widely used (and cited) today.

Q4. What do you do when you are not working on your research?

In retrospect, I should have stressed less, pursued studies more in things that just interested me even if off the beaten path, enjoyed other things, and invested the $ I had in Apple, Ebay, Google, and Amazon when I first started using their products or services...I would be retired :) Today, I find a mix of talking with my family, taking piano lessons, doing photography, taking late night walks, talking to people about their business problems, hacking at the odd tech a lot of fun.

I look back and see things went pretty okay - could have been better, and could have been much worse. I personally would do the PhD again - I would probably take it more seriously but also I would also know it wasn't a life commitment as much as a commitment to a life of thinking. At least for me, I found over time many changes and opportunities that worked for me along the way. It was good I found things through my MBA that (1) followed the money (2) had good demand (3) I did like (4) I was good at. Consulting worked for me - but it was not a life goal, nor was it the 100% fulfilling passion of my life. But it was a practical way to do well and like what I did. I had lots of doubts along the way, and still do. But my family is well, the kids are good, and I like what I'm doing - and I'm glad I had the modest academic career I did have.

Yourself and others here have pointed out the uncertainty in evaluating the direct opportunity cost of doing a PhD vs being in the industry. Clearly there's no right or wrong answer there and it really depends on the individual and many factors. I would just like to point out that there are some "indirect" benefits to doing a PhD, that I myself didn't realise until I was much older.

Depending on your background and circumstances, doing a PhD may be the most challenging thing that you have done in your young life, primarily due to the inherent uncertainty that exists within research. If this is the case, then what you're learning is also how to cope with and manage these challenges, and a good deal of self-knowledge. Once I mentioned in a conversation with a senior person in a company that I learnt exactly how my own learning curve looks like after doing a PhD, he was so impressed that he practically offered me a job there and then.

In addition, you're learning to solve problems using a high degree of intellectual capacity, so this is what you can eventually "sell". There are many programmers and, but if I was looking to hire one, I would probably pick someone who can understand and solve the bigger problem with less actual programming skill if the choice came down to that.

There is also an element of "moral" satisfaction you get from doing research, depending on your area, as it is not usually geared towards making more money for someone else - definitely possible to find this outside research but not that easily within the industries employing STEM professionals.

There have been a lot of answers and I just want to share my experience in that academia-industry topic, However, I don't have a PhD, though.

TL; DR

You gave the answer: "the grass only looks greener on the other side". This applies both for the being on industry/being on academia discussion. But also in your specific question regarding your PhD degree, It might not have a clear or real impact for you (you are on this side), but someone outside the project, even outside the main field of your project (the other side), could find it useful and interesting, and could find a high value in it.

Since I while doing my bachelor degree, I had been changed my focus/field between industry and academia, not in a bad sense of indecision, but sometimes forced, sometimes aimed and found that there is a narrow, fuzzy band where the two can co-exist: R&D in industry, well-driven R&D.

My interest never was the money, but sometimes it was my need, but what I most value is to have life/work balance and to enjoy what I do.

Answering your student questions:

I wish to go to graduate school, but I also fear that I will miss out
opportunities to make hundreds of thousands of dollar per year working
in industry. I also wish to be financially independent and have an
early retirement. Can doing a PhD for five years offer this reality?

If your priority is money in short-term, go to the industry as soon as you finish your undergraduate. The matter is that with postgraduate, you have chances to increase your income in the long-term and enter directly to a higher position than a junior one. But note this: chances.

Programming and software development are highly valued skills in
industry. Almost all jobs nowadays requires some form of it. Do you
think your degree has prepared you to be competent in these areas?

Just software related degrees prepare you to be a professional programmer. Experts and professional programmers make beautiful and excellent programs and applications. But someone who can code at a decebt level, and have experience in another field, could link these two skills to articulate a software solution for a non-software problem/opportunity. It is a personal decision which skills to improve and to what level.

Do you believe in the theory and methodology you are developing? How
do you know that your model can be used by actual people, like the
products people develop in industry?

When you plan a project in academia (Thesis, research, etc) and you like and enjoy your field, you could begin with higher expectations of your project and yourself. Even you could overestimate what you can achieve. But when you are executing the project, you could become the main critic of your work and think it is useless and has no impact. But as you said, "the grass only looks greener on the other side", others could see the value of your work more than yourself.

What do you do when you are not working on your research?

If at this stage of your life, your priority is your career, it is completely fine to have work/academia-related hobbies. If you are ok with your career and you want to spend your out-of-work time in gym, traveling, sports, family, sleeping, volunteer that is fine too.

(These are not particularly much advice for getting a PhD at all but for life in general.)

You should work on stopping to focus on feeling "valued".

The point of doing a PhD is to get so damn good at something so most people have no idea what you know or what it signifies. The more you know the lonelier and further between every new person you meet who happen to know the same thing and know how to value it.

So you should learn to find happiness in your work and focus on the excitement you have for your field and your subject. Strive to distance yourself from wanting praise, because if you get any good at your trade, most people will simply have no clue how good it even is.

If all goes well, you are supposed to surpass your own teachers... maybe by such a margin that they don't know how good your work is or if it is worthy of praise. By then you will have needed to learn how to find happiness in your own work and to trust your own skills and instincts enough to both value it and verify it all on your own.

Remember why you ever pursued PhD and find happiness in what you do. Everyone in academia came for science and stayed for science. If you did not, then you should leave for academia has nothing to offer you. Academia is the place of science for the sake of science.