I don't want to be promoted, since I really don't want to manage people, so I instead went on linkedin, waited for headhunters to contact me, got some job offers, and took them to my manager asking for a raise to match their offers. Since my job is a necessary part of the process, one of the other companies was desperate to fill the spot, and offered me 50% more than I'd been making at the time, but my manager knew he couldn't afford to let me go, so I managed to keep my nice remote job, but now with much better pay.

It's been 5 years since then, and my manager still understands that I'm one of the only people in my department who can actually do the work correctly every time, so I've got plenty of job security. I'm still somewhat worried that they'll get rid of me when he retires and gets replaced with someone else in the next year or two, but I'm still getting plenty of headhunters, so all that would really mean is that I need to get used to working for a different company that probably has better surveillance to make sure I'm actually working during the entirety of my shift.

That’s not necessarily true or bad.

I don’t want to manage, and they can promote me to work on new stuff, while still maintaining critical services.

Let me introduce you to be Peter principal: As long as you do your job well, you get promoted. On the flip side this means that eventually you arrive at a job you don't do well and that's where you stick because you can't return to your old position but neither will you get fired because you work for the company too long. That's why there are many people in middle management who did their job well until they had to manage others which isn't part of their skill set.