I think this is the right set of questions. I can add my own anecdotal experience. In the past, I ran voice chat servers, IRC servers, forums, rsync and sftp servers. I gave people a way to have their own small communities that were mostly free of censorship provided they were not breaking the laws of my country. For a while, those things were popular, but as the big centralized sites came along, they designed their UX to be low friction and high endorphin reward. They added more discoverability and ability to have bigger communities. People preferred this over what I could give them. With time, my IRC servers lost favor for things like Facebook messenger and Discord. Rsync and SFTP were "too hard" and everyone moved to Dropbox and related sites. My remaining SFTP server is now just hit by bots, very confused bots. I shut down the last voice chat server because people would only use it when Discord was offline. On top of all that, internet trolls have evolved beyond psychological warfare. Now they are good at scripting uploads of bad content and auto-reporting their own content to take down domains and servers regardless of how fast response-driven moderation is. This means I would have to set up forums to require every message to be screened, or use some expensive machine learning and that gets into a whole mess of privacy problems. It's just not worth my time and effort to play those games, especially given the lack of interest in using smaller communities.