What decentralized protocols try to solve, and what the centralized web has failed us with, is data ownership. Users should have full control over the data they produce, and be free to migrate it to any other node without losing access to the service they're interested in.
I think Nostr looks very promising in that sense: https://github.com/nostr-protocol/nostr
Mind you, I don't think social media is worth reinventing. Connecting everyone on the planet is wrong on a societal level. But P2P services are a good fit for building smaller communities, which is a crucial missing component of the design of the WWW. I'm still hopeful that something built for the masses can take over the current mess we're in.