I've created work that wasn't hard from a computer science point of view but was transformative of how my company worked. And the work was my own idea. That was more than satisfying.

Working on computer science for its own sake isn't a draw for me. Helping people is. Your values are up to you, but don't be surprised that working on abstract problems rarely equates to adding real world value unless you look for a job where that's explicitly the case.

Also don't overlook the dynamic that you're being paid now rather than being the customer like you were in school. Your career is ideally going to be fun and enriching overall, but don't let yourself forget that's secondary at any given time to providing the value you were hired for.