To add another point of anecdote, I've also left a bad dev job for less money but better mental health overall. Such a good decision, but a difficult one to make.

Higher amounts of money yield diminishing returns. It's difficult to balance it with the added benefits of a low stress job (or one with a better commute, friendlier colleagues, etc), but putting the effort it's totally worth it. This includes being honest with yourself about what makes you happy in a job, which is actually much more difficult than it sounds (as it always it when you need to be honest with yourself).

I’ve never left a job and regretted. My criteria for a job are technology, environment and money. Once the technology got out of step with the market, it’s dangerous to stay at a job. Once you’ve been at a job long enough, why not leave for a better environment? As far as money, all other things being equal. Why not leave for money?