[wtallis]

What you're referring to, I'd call a historical archive, containing many backups.

When I think about a backup, I'm thinking in terms of recovering last good state after a drive failure or catastrophic filesystem corruption. I don't tend to think of a backup as implying a deep history unless that part is explicitly stated. That distinction was easier to notice back in the days of backing up to tape or optical discs - you don't expect each tape/disc to contain a version history, just a single snapshot, and you don't expect your collection to retain long-gone files unless it's an ever-growing pile of tapes/discs.

In that mindset, it's not reasonable to expect that a backup service necessarily provides the full historical archive.

[justsubmit]

> you don't expect your collection to retain long-gone files unless it's an ever-growing pile of tapes/discs.

Rule number whatever of backups: Don't discard old backups. Bitrot occurs, and people make mistakes, and newer backups can have flaws that older ones don't, which will go undiscovered until it's too late.

We're not talking about piles of tapes, we're talking about virtually unlimited disk space. State-of-the-art backup software chunks and deduplicates data and stores snapshots of directory trees. For most cases, there's no reason not to keep a subset of old snapshots, and many reasons to keep them.