> We used to have Usenet, which was fairly decentralized in the sense that each server/provider could decide to ban some groups and admins and moderated groups

> We used to have Usenet, which was fairly decentralized in the sense that each server/provider could decide to ban some groups and admins and moderated groups could ban users. We still have Usenet. I still find it work better than many of the newer alternatives, although I have only started using Usenet in 2019.