I also think an interesting question is about how they are formed. The flavor of a forced settlement (prisoner transport) versus an opportunistic settlement (rich resources) is going to influence a lot of the behavioral patterns of the people.
I have my Mastodon instance broken out into docker containers running on one of my “beefy” servers in my homelab. I don’t regret setting it up at all, but I’m glad I’ve resisted lemmy/kbin/etc. With Mastodon, I don’t feel any guilt about keeping it to myself, and having no anxiety about someone losing content. I tend to feel like if someone is creating content on a platform I own, I have an obligation to treat it with respect, as opposed to how I feel about my own content.
Always welcome! I share my thoughts freely to help! This is a fascinating set of questions, and I can’t wait to see what people are sharing.