Arweave has a compelling design for long-term public archival along these lines, with an explicit concept of 'endowment' to predictably cover the costs of future storage.
The Arweave endowment is just one of these crazy schemes crypto folks think up to make their systems harder to understand so you don't realize how they scam you. I'm not saying Arweave is a scam, but that's exactly what this endowment structure is. They may as well just mint extra tokens to pay whoever the endowment pays, and delete tokens that would have gone into the endowment.
BTW, Arweave doesn't guarantee permanent archival - nodes are free to decide what to archive.
I haven't followed Arweave closely at all recently but the creator seemed genuine and capable enough to warrant attention. As to tech itself, assuming commodity storage costs continue to drop ~indefinitely and somewhat predictably it feels intuitive to me how such a scheme can be viable. It's ultimately a bet on ever-reducing storage costs.
