Protocol Labs (the guys behind IPFS) have been working on https://filecoin.io to address this exact concern – incentivising people via micropayments in their cryptocurrency (filecoin) to pin and seed files.
Yes it's really good to have the economics (mechanism design) and infrastructure in separate layers.
Also, I'd argue more important than even having the hosters is having the content addresses. We need well-known immutable data for people to want in the first place. And traditional system bury data under so much mutation/indirection that it's hard to know what that content is, or that content-addressing even exists.
I highly recommend https://www.softwareheritage.org/2020/07/09/intrinsic-vs-ext..., which is about software heritage trying to get the word out to the larger library/archival/standardization community that content addressing and other "intrinsic" identifiers are possible and desirable.
Git and torrents I think is the best counterexample to the above, and there is probably more legally-kosher git and bittorrent usage, so I am especially bullish on Git hashing being the bridge to a more distributed/federated world.
