I would bet any amount of money that at least 50% of lemmy posts are shitting on capitalism. Couple that with the fact that people tolerate some amount of tankie'ism, I'd say lemmy is extreme.
Let me ask you this, if you had a website with a community that relentlessly mocks communism and/or socialism, and lets some nazi posts rise to the top, what would you call that website?
I don't know anything about Barbie so I can't say anything about that. But I know that not all of lemmy is extreme, of course there's gonna be some normal everyday content.