>Section 230 was supposed to make social networks public squares

Wrong. There is nothing in the statute that implies neutrality.

Section 230 was to enable online platforms to engage in good-faith community moderation without fear of taking on undue liability for their users’ posts. Online platforms are within their First Amendment rights to moderate their online platforms however they like, and they’re additionally shielded by Section 230 for many types of liability for their users’ speech. It’s not one or the other. It’s both.