In the real world, barbarians are foreigners that talk funny and act weird. From the perspective of an arbritrary (self-proclaimed) civilization, they are uncivilised. Of course the notion of civilisation is entirely subjective, but the word 'barbarian' could be applied by people from a certain population centre to outsiders that have a different language and culture. So with the focus of BG3 on the city of Baldur's Gate, the single big city in the area, it follows that locally the term barbarian should be reserved for people that grew up outside of the city.
Now it could be that the term 'barbarian' should be taken as meaning as something entirely different in D&D. I really don't know, I'm not a D&D expert at all. But I do know how to look things up, and
this description of the D&D class that Google found for me does seem to show that the concept of D&D barbarians is not very remote from real world barbarianism:
"
People of towns and cities take pride in their settled ways, as if denying one’s connection to nature were a mark of superiority. To a barbarian, though, a settled life is no virtue, but a sign of weakness. The strong embrace nature—valuing keen instincts, primal physicality, and ferocious rage. Barbarians are uncomfortable when hedged in by walls and crowds. They thrive in the wilds of their homelands: the tundra, jungle, or grasslands where their tribes live and hunt."
I still think it strange that Karlach and my Tav barbarian grew up in Baldur's Gate.
