I know this for sure....a 20yr old usually doesn't want to play with 50-60 yr olds, and 50-60 yr olds don't want kids in their band.
When I was in my twenties I was in a band with three guys in their 40s. It was a full-time gigging band, though, so the social aspect was a non-issue. I’ll tell you what, though-I don’t want to be in any band situation with a grumpy old fart. Even if he’s younger than me.