The only two kinds of successful content types that I’m aware of are pirated movies on Torrent and cryptocurrencies on the blockchain. They all depend on centralized discovery(torrent websites and exchanges).
Which makes me wonder, are these decentralized websites or social media platforms attacking the right problems?
It's an alternative transport, not application layer. If you can imagine doing anything with the world wide web , or ftp, you can imagine what this is for. It can transport hypertext files around, or whatever other file type you want.
In the web case, it'd just be some local http files you could open in a local file origin. There'd be no server. But that's still a way to exchange whatever art or media you could ever imagine.
We are bounded only by imagination. The internet is built around the Internet Protocol (IP), a way of streaming data arbitrarily from one computer to another. It has been up to us to imagine uses, to chase new possibilities. What do you think the use cases for IP are? Can you see what that made possible? Your question is in effect that, and trying to grasp at how broad, how possible, how potentiated this great work is is dauntingly hard, for we could share any type of content we want with either.