That's the sad thing about decentralized services, they follow a standard that doesn't get updated. Facebook and slack can add new features every month, but adding a new feature to email or IRC is so difficult.
Okay... I agree adding features to email and IRC are probably not the easiest things in the world. There are a number of useful features that have been added to email over time though, and I don't think decentralized control of the protocol is the bottleneck. Wave might or might not be a good example.