I wasn't talking about living groups. I was just saying would any character call themselves a barbarian? Wouldn't they use the term to describe others, not themselves? It's just about making sense from the perspective of the character.
(Not that characters use class names about themselves anyway, so it's all very abstract and hypothetical).
Yeah, D&D class names are a bit weird. I can see someone calling themself a wizard or a druid but I don't think many people would refer to themselves as a fighter,* rogue, or barbarian. In one of my sillier campaigns, every PC went to adventuring school to learn the ropes of their classes. That means barbarian characters had to take courses in barbarism.
* I've heard people refer to themself others as a fighter, short for prize fighter, to indicate they are a boxer.