there are only two modes, with no medium: either overwork yourself to burnout; or do a minimal amount of stuff with no clear path on how to do more and feel like you're unneeded/unappreciated

This. So much. I was on the systems committee, and we had two people overworking themselves to burnout, and the rest of us were doing a minimum or nothing. The two overworking people were too busy putting out fires and keeping the servers running to mentor us, which ensured that they remained overworked and we remained underused.

And I concluded "It must be me. I'm too incompetent/untalented/disabled for a career in computers [which was what I was aiming for.] I'm a liability and that's all." So I quit. Years later, I discover that there were a whole lot of people in the same situation.