Mild Cohost addendum: I spend way more time on Cohost mainly because it serves as a single (large) "space" for me, but an order of magnitude more users would really make me start wanting a way to subdivide the entire site besides tags, which have no meaningful way of enforcing norms.
Also I do think about how "enforcing norms" can and often is a tool of social oppression in a community. Like a knife, it is a tool that enables the intent of its weilder, whether for good or for ill. This is partly why the platform itself still matters—Cohost staff are who set the boundaries within which subculture norms can operate, and who can say, for example, "any subhost that has a rule against trans participation will be deleted because fuck that bullshit".