In the mastodon space, folks are figuring out this exact same issue. For that space my team wrote about 100 lines of javascript code that made it far better. If you click on a remote link, it asks you ONCE what your home server is. And after that the JS automatically writes all URL's to funnel you back to your home server to interact with them. Can share that if folks want maybe it could be adapted.
would be a good idea to make a tag or an alert featured on the magazine if it appears no mod has logged in in over X days, with a link to apply to become one. Not sure who would approve that takeover tho... but a tag alone would be a warning to users that it was functionally unmoderated.
Our goal: to be a better place for new users to onboard, and to be an organizing hub or those looking to spread Mastodon and the Fediverse. Opening up all the source code so any Fediverse portal can reuse. For example a SpreadKbin site could modify and use.
Andreas, Did you see this? This is where we are building for, would appreciate any notes to this idea and if it would alleviate your concerns about centralization: our goal would be to swap out one sever and swap in new ones over time to spread out far beyond four overall. And Mastodon.social staff are not involved and would not have any say over the four.