It's a little depressing Moxie believes federated protocols can't compete with unfederated/proprietary ones. I don't like the idea of all future innovation taking place in the Slacks and WhatsApps rather than the IRCs and SMTPs.

Are there any recent counter examples of successful federated protocols?

It would be an interesting thought experiment to design a protocol that started with the basic features of IRC and incrementally layered on new features in backwards compatible / gracefully degrading ways until you arrived at Slack. Of course it would be a lot easier with the benefit of hindsight than if you started in the 1980s.