Bassist here. It's a unique sort of fulfillment; it's not "fun" like playing a game, but it's a certain kind of joy. Gives life additional meaning somehow. Hard to say!
These days I practice pretty often because I'm building some chops, but part of my connection to my instrument is how little practice I actually need. I have an ear for it so I think it's very easy! There are bassists out there who wank around and play a lot of busy parts, slapping and popping and such and I never enjoy that. I just want to be the foundation to a song, have a nice tone, contribute my part. If I wanted to be out front with a huge ego I'd be a guitarist.