You know what's interesting? A Decentralised media platform used to be huge and actually is still huge: Torrents. There's a huge community that consumes media that's not hosted anywhere particular and there are apps like Popcorn Time that offer viewing experience almost as good as Netflix. The problem, of course, is that up until now there was no way to reward the creators and almost all the media consumed on Torrent…
Bitcoin and bit torrent suffer from the same decentralization problem. Centralization will always be cheaper or the system will fail to sustain itself. Either these systems are not profitable to participate in and no one bothers, or it is profitable at which point it will be dominated by key players that either participate in the network or simply launch a centralized competitor. Specialization leads to cost cuttings and the large actors increase their quality, margins and market share squeezing out the decentralized players.
The one caveat to this is that torrents are cool because its a system that can arguably edge cache better than CDN locations but with today's low upload speeds and pings for consumer connections it seems the CDNs do win.