Григорий, so yeah, the software I'm writing this from, Smithereen, does have a limited scope. I plan to call it complete at some point and then just stop actively developing it. I do have lots of features planned, most of which no one has attempted in a federated social media service before, but it's still a finite number. Like photo albums with tagging. Or global search for users with bloom filters for peer servers (this needs testing in practice).