This is the one that came to mind for me too. In North America and Europe, Facebook skews older, and older people tend to be relatively moderate-right.

Gab is certainly "far right", but that doesn't mean those views are uncommon. Centrist viewpoints have shrunk, pulling what was previously considered "far" viewpoints into the mainstream. I think it's undeniable that a website where many (most?) of the userbase would advocate against the peaceful transition of power in the US should be labelled "far right".