> Didn't onlyfans severely limit the type of content creators could make and distribute through the platform, just like valve here?

Well, this coverage identifies two restrictions that Valve is enforcing:

(1) No video footage of humans. Animation only.

(2) No incest.

Onlyfans clearly hasn't implemented restriction (1).

If they've implemented (2), that seems like much less of a problem as applied to onlyfans than to animated content on Steam. But even in the case of Steam, there just isn't a constituency for being pro-incest. This is the last political fight you'd want to get into.