I wouldn’t say he has FYM yet. Enough to maybe FIRE but more than cash, he’s in a position where almost any tech or related company would hire him, pay him a ton, and let him work on what he wants to do. Essentially, tenure at a university but paid 10X as much.

I certainly don't have "fuck you money", but these days I think most competent tech workers can easily get jobs elsewhere, so I don't think it's a big, risky move to quit your job.