I'm in a Dad and Sons band. Two pairs. So, we hit both ends of things. I completely enjoy gigging with younger cats. They bring fresh ideas to the scene. The older cats teach; the younger cats bring the energy. Its a formula that Motown made a lot of money on.
Regarding clothing, at the last gig, the two younger cats turned up in the shorts and flip flops. The older folks were in cool muso duds. And, all are in shape. Nevertheless, we kept the dance floor packed, had a wide age range raving about the band at the end of the night; and then the club manager explains that he's going to try a few other bands over the summer (club manager speak for "you're fired").
So, forget your stereotypes. People are certainly tribal and discrimination based on age, gender, skin pigment, and religion etc etc is alive and well. It just comes naturally. Forget about the rules. They mean nothing anymore. People are morons.
Club managers are still buttheads. Gigs are competitive and don't pay squat. It's a wonder we do this stuff at all.
And, then through all this train wreck human behavior, every now and then, you do get the gig where it all comes together.