What are some interesting p2p or otherwise decentralized content platforms today that could be next to gain critical mass in users and content? I know webrtc l

What are some interesting p2p or otherwise decentralized content platforms today that could be next to gain critical mass in users and content? I know webrtc lets you do things like peertube, webtorrent, and p2p videoconferencing, then we have mastodon and some other social platforms, and various relatively unpopular IM platforms. And good old email of course, maybe that could even incrementally bootstrap some new usage model eg in IM.