You use "just" too much - I'm 48 and what, you think you're better than me because you're sitting at home all zen like and enlightened, not lugging gear to venues, playing to three people and a dog?
Ahh, I get it now!
Only kidding - each to their own, but I would miss the playing with others aspect too much to do what you're doing - and my songwriting extends beyond "just" playing bass - I write lyrics and I offer ideas to the other guys, not that I can play their instruments, but I can ask "can you do X, can you play it like Y, how would Z sound?" - TL:DR I enjoy the instant back and forth collaboration in a room.