About 4 years ago, I switched from a higher-paying career to a lower-paying one that was more fun. I ended up in a freelance gig where, because I had FU money, I successfully negotiated for part-time hours at a higher hourly rate than the extremely under-market rate they were offering for full-time work, since they cited their budget as the reason they couldn't go higher. Then, when they offered me a permanent position, I argued for a substantial raise to get my rate back up to what it had been previously (based on my high productivity), and also to keep my part-time hours. And they agreed.
Now I'm in a position I like, doing work I enjoy, in a rewarding industry that pays less than the one I'd been in, but I'm making decent money and working part-time hours. So yes, I care less about salary, but because I had FU-money-based confidence, I ended up making an hourly rate close to what I'd made before, plus benefits.
Caring less about salary is great. Caring less about risking your job is also great, since it can lead to a stronger bargaining position.