Civilisation VI's barbarians work much like they do in every other game in the series. Well, mostly. There are a few frustrating exceptions.
Frustrations that Gotta Keep Moist has absolutely nailed here.
First, those early-game scouts who somehow always manage to stay one hex away:
And second, those god damn trade route raids:
When Firaxis ever get around to introducing Steam Workshop support for the game, I hope the first thing we see is a tile improvement called a BEAR PIT.