“It’s the only thing that satisfies my compulsion” is a good reason to do something IMO. Certainly not useless for you (even if it would be for most people), assuming it actually is the best thing you could be doing with your time that satisfies your compulsion. I definitely relate though, I find it very difficult to prevent myself from writing.
what are the actual criteria you’re using to evaluate them right now?
What I’m trying to get at is “how much does this hobby make my life better outside of me finding it fun”. I think the two that come most to my mind are whether the hobby causes you to make friends and whether it keeps you in good shape, but those are pretty surface-level and obvious. There are lots of other ways a hobby can be helpful (e.g. it can advance your career, it can fulfill a desire in you to help others, it can make you money). But those all seem like saying “good books are ones with a relatable main character and narrative tension”, they will help filter out many bad (and a few good ones) but they’re to simplistic and general to be much help in finding a truly great one. Many great books are great because they did something unique no one else did, and probably many great ways to spend your time are great because they have some unique massive advantage that’s difficult to find anywhere else.
For math I’d like to submit this series: “A hard problem in elementary geometry” by fields medalist
Timothy Gowers. It’s a 6 part series where each part is about an hour long, of him trying to solve this easy-seeming-but-actually-very-difficult problem.