My position in the company is pretty good and I could probably ride it out until I die or the company picks up on the fact that my output has dropped due to the lack of caring. But that eats at my soul and it isn't fair to my coworkers.

Let me push back a bit on "isn't fair to my coworkers".

I have worked many times with a cranky senior technician who has seen almost everything before and barely gives a shit to do more than the bare minimum.

I adore working with this person. There's never any drama. They get their work done barely but consistently before deadlines. Their work is done correctly more often than my own work is (and I'm quite good, honest). And once in awhile they're generous enough with their time to pull my ass out of the fire of my own incompetence (everyone fails sometimes) with their advice.

Once you've hit the point where things are easy for you that are hard for everyone else, I find your bare minimum effort is more than fair and generous to peers like myself.

Gamedev does not necessarily pay badly, depending on your location. But getting hired to do it might be tough.

I got in by getting hired in a game company doing something related but it wasn't directly gamedev. After a while, I was able to transfer to actual gamedev and I'm now on my third big game project, having shipped two.

I tried getting into gamedev directly, and that was honestly pretty soul-crushing.

Work your 40 hour weeks and then go home. No more, no less. While you don't need to formally track your time, treat that as a rule.

Get a Hobby. It doesn't matter what. Get violin/trumpet/piano/... Take lessons, and commit you will practice 1 hour per day for a year. Buy a hand plane, chisel, and dovetail saw and build some wood boxes. Get a good cookbook and go through it making every single meal one day at a time. Get a tatting shuttle and make some lace. Get a pen and write a novel. It doesn't matter what you do, just sometime. don't spend too much money until you are sure that hobby is for you, but don't buy junk tools for your hobby either (perhaps budget $1000 every 6 months for hobby things - even if you can afford to spend more)

Don't forget your wife in all this! This is last because you are mostly likely to remember what is last. Take her out dancing, or just dance in your living room. Have nice dinners together. Plan a board game night. If you budget for a hobby make sure she has a similar budget for whatever she her hobby is. There are times to do your own hobby and times to share a hobby. Keep your marriage alive - this takes effort, so make sure your wife is one of your hobbies.

This does sound like a burnout, i would recommend to try and rest a little bit for a feel days, maybe a week to put your mind at easy if possible, also gamedev can be a good hobby for taking your head out of work, look on itch.io for a game jam and try to have fun along the way

Find a new job in software. 15 years in the same field is a very long time!

What should I do / think about?

I've been in your shoes, and I did eventually make a move for a challenge.

Then I moved back, after I got that urge out of my system. So my best advice, that I followed and it paid off, is leave on good terms, if you leave.

I had to process the transition that I'm no longer primarily paid for making things but for availability and mentorship.

If I was paid hourly for making things, I could never make a living wage. I simply work too fast initially, and I no longer waste enough hours on fixing my past mistakes.

So now I spend an inordinate amount of my time training on whatever amuses me that might someday be valuable to my employer. And I prioritize taking breaks in my schedule to mentor and explain things to peers - whenenver I can afford to. I'm genuinely very good at what I do, so "whenever I can afford to" is astonishingly often.

Eventually that transition to availability and mentorship led to a promotion into roles that demand it more. So I accepted a promotion into management and then read a crap ton of management books.

I'm still a renegade manager whose boss understands that I'll do some coding whenever I please...I mean, whenever my other duties allow.

Bro, I’m 7-8 years in and I feel this. I think about this a lot lately.

Pivot to ED infosec, get a security clearance, work for the government or government contracts.

It's within your field, it's sexy AF, it pays extremely well, and it puts you into a different and rather interesting peer group.

My experience may not be relevant because I always quit when I had toxic managers who were killing me every day, and it may be different from yours, but anyway here are random stupid thoughts:

• "off highway farm equipment": what it this? what language are you using?
• you want a kid and your "position in the company is pretty good": don't quit now!
• game dev: it seems to be awful unless you have a lot of money and write indie games like the Stardew Valley guy (Ubisoft in France is famous for being a burnout machine)
• embedded systems: I would shun embedded dev who uses C and is focused too much on electronics, I would focus on higher-level stuff like C++17/20 or Rust
• I would focus for some time on reading books and papers, and trying new solutions, improving my work in a way that could be applied to another company, like CI/CD, use new languages, find ways do check the code or improve it, fix or change stuff here and there and take notes that can I could reuse...

Anyway, what is your current job right now? What are you doing daily?