I think it important to point out here that the crucial factor here is scale and efficiency. Grimmoire was/is a client that demonstraded more fancy queries, and you can do all sorts of things that way. But insofar every-day use concerning large sets of people and a lot of events etc etc, the day to day way to do this is to rely on relay-feeds (that may or may not have done all the heavy lifting for you, leveriging those fancy queries themselves). What is boils down to, is that 'location' is still important, but that identity (by extension social graph) and content/data is not strickly bound to a location/server/relay. So whenever for whatever reason, one of these relays you have been leveraging (for what they are good for) starts acting up, you have means/alternatives such that you don't instantly become marginalized down to your own website or some alt-platform neither of which anyone will ever visit ever....you probably won't even have to leave your app to 'reconnect' with someone