The Colombia Journalism Review (a big journal we used to read when I was working as a reporter) just published this 20 year retrospective on Wikipedia. And they talk about some of the moderation innovations over the years that have helped stabilize the site.
Articles such as the “COVID-19 pandemic” are subject to semi-protection, meaning that anonymous IP editing is not allowed and that any contributors must register an account. Other articles have more extensive protections, such as the article on Donald Trump, which has long been subject to extended-confirmed protection, meaning that only Wikipedia editors who have been active for 30 days and who have performed at least 500 edits can directly edit Trump’s page.
I think Wikipedia is an interesting case study, and that some of their innovations may make their way to larger Discourse instances, and perhaps to larger open source projects as well.