Nix-native user data backup/restore?

The section describing “hash backup” in this blog post on backup strategies made me wonder:

How well-situated Nix is for implementing a user data backup/restore toolchain?

Hash backup tools hash blocks and store them (similar to how Git works)

Garbage collection of expired backups is easy, as you just delete unreferenced objects. Deleting a backup in the middle of a backup timeline is also trivial.

Deduplication is easy since each block is hashed and stored once.

Data verification against a client can be done with hashes, which cloud providers can send via API responses, saving download bandwidth.

Possible to deduplicate data shared among multiple clients.