Yeah, so we'd need something sort of like bittorrent-with-web-seeds for any file more than a certain size, and maybe some pre-concatenated optimization where the whole page and its assets become a single file under such a system. Maybe IPFS might be a useful layer?
Anyway, "hosting" would mean two things: 1: "I attach my name to this content and it's always locatable as a tag under my name", and 2: "I dedicate some static resources to always host this content, whether or not it's popular enough to also propagate to other nodes in the swarm, I will always seed it".
Then simply having that seed-box allocate a certain amount of its space to each subscriber would be all you'd need.
Succession protocol would have internal uses too; they could say "Hey this subscriber has some really popular content, let's move it to a faster node", and the same primitives would track that move.
I feel like most of these pieces already exist, the trouble is there's no longer an expectation for an ISP to provide hosting to customers, so providing better hosting isn't a differentiating factor. (Not that there's meaningful competition in many places anyway, which may be the root of the problem.)
Which all adds up to people not realizing there is or even could be an alternative to hosting their images on perpetually-unprofitable-and-thus-inevitably-transient services like photobucket, imgur, and their ilk.
