To make the web distributed-archive-friendly I think we need to start referencing things by hash and not by a path which some server has implied it will serve consistently but which actually shows you different data at different times for a million different reasons.
If different data always gets a different reference, it's easy to know if you have enough backups of it. If the same name gets you a pile of snapshots taken under different conditions, it's hard to be sure which of those are the thing that we'd want to back up for that particular name.