This is just my opinion, but I think the answer starts with first replacing authentication mechanisms, thus allowing any group of people to try different social apps, forums and chat servers using their common auth.
In my Utopian world, small groups of technical people would host OpenLDAP servers and replicas. They would front end them with some open source SAML2/OAuth providers. That would allow them as a small group to have forums, chat servers, blogs, email, etc...
Their circle of non technical friends could then utilize all the services the technical folks share the support of. If the LDAP master drops out, someone else promotes their replica to master.
Why all this? No nation state back doors and potentially less risk if people reuse passwords, since this group can also host email.