While we can wish very hard that credibility is a tradeoff with anonymity, any real world data shows that reality is far from that simple.
It is not hard to find Facebook groups that are far far more toxic than most Reddit groups, for example. Most USEnet identities were not hard to associate with real world identities, but the quality of those posts was not obviously better than those that weren't. And so on.
There are differences between the groups, but perhaps those have more to do with whatever contemporary issues that carry social stigma than with signal quality. And social stigma is very different between societies and tends to change over time. One generation can upend them completely, and any solution to social credibility must take a longer aim than that.
Maybe that’s not such a bad thing.
Anonymity on the web has led to some pretty atrocious behavior.
Plus, at this point, anonymity on the internet is an illusion anyway.
Just use existing trusted CAs to issue personal certs based on some reasonably robust verification process.
Maybe the AI apocalypse will help fix the internet by making anonymity untenable.