I think a lot of content creators would jump at the opportunity to host their videos with another provider (or even host it themselves, maybe on a p2p platform), but from what I can see it simply doesn't make monetary sense to go anywhere but YT.
It would be cool if this could be done in a reasonable decentralized way, but I think even a decentralized service would go a long way to fostering competition in the hosting/encoding space.
I don't know how decentralized recommendations would work beyond a simple keyword search. They're kinda subjective, so I think that's easier to do with people making curated lists instead of something automated.