Basically Nostr is as functional as twitter now but it is a protocol that can do a whole lot more. And any developer is free to just do it. So there is a lot more development to go. It is totally possible that Nostr integrates most social apps you use in the future like the smartphone did to a phone calculator and camera. Why not have YouTube, Spotify, twitter, Reddit, wiki leaks, eBay, cashapp, homeautomation, etc combined ? We are just scratching the surface :)