> no website could accept user content, ever, and you are effectively suggesting the end of public communication on the internet?
That does not follow. Just like financial services are forced to KYC, there would have to be some similar provision. For example, a site might choose not to have anonymization and then liability passes through a KYC chain. If a site wanted anonymous then the burden would be on moderation before it became public. I think this probably already happens in large extent where images are scanned to avoid bad things appearing on public sites and there is already liability around that.
I know that isn't a popular position. It would change the entire character of the Internet. And it couldn't just be thrust upon people since the current contract is one of promised anonymity (even if that is probably not true wrt state actors).