&gt; The major upside (for me) to federated systems is simple: choice. Choice over the client you use. Choice over the servers you use.<p>With a centralized system, you cannot choose the servers you use, but you can still choose the client, if the procotol is open and versioned.<p>As explained in Moxie&#x27;s post, being able to choose the servers you use doesn&#x27;t help if all servers use the exact same protocol with the exact same features, frozen in time.<p>&gt; The reason I think that things like email and SMS are still so prevalent is how you don&#x27;t need to care what service the other people are on, you don&#x27;t need to worry about how other people are going to talk to you, it all just works.<p>You&#x27;re right, people continue to use email and SMS because they are available everywhere. But people also use things like Facebook, Skype or WhatsApp because of email and SMS limitations.