So then it potentially becomes impossible to create a startup that replaces existing social networks due to moderation requirements. Facebook and twitter got lucky they didn't get killed this way in the early days. This is similar to the criticism on the EU automated copyright violation detect requirements.

If moderation laws essentially make it impossible to build new mass platforms, then that creates a very strong case for having rights to have unrestricted open access to existing platforms, does it not? For example, the networks then wouldn't be able to issue lifetime bans at their discretion.

It's not difficult to create new social media platforms. They're created all the time.

If your newborn community attracts so many bad actors that they become such a drag on your business that you can't operate because of the liabilities the create for you, you are a victim of these bad actors. You're not the victim of a functioning legal system.

I don't get it.

Excuse the analogy but are you staying that if someone plans a protest in my Minecraft server, and the protest turns violent - I can be held to blame for that?

If someone told you people were plotting to overthrow the government on your minecraft server, and you didn't act on that, you could be culpable if that report turned out to be true. If people died, their next of kin could hold you accountable for civil damages in a wrongful death suit.