Not really dumb. I do use them too but with Borgbackup on the top (since they support it natively).

I found Borgmatic ( https://torsion.org/borgmatic/ ) to be the best way to run my backups. It takes care of everything from pruning to verifying the checksum etc... and it integrates with some monitoring (like cronitor).

So Borgmatic + rsync.net is the best combo

No, you are keeping it simple.

I am using rsync to rsync.net from multiple different hosts with different configurations. I run the same command on every host running variations of *nix, no messing about with different tools needed.

I need to store on Azure for DRP reasons: we would DRP to azure and need the bandwidth.

Also, storing the ZFS snapshots on Blob storage would still require us to retrieve the entirety of the 80TB before being able to use it. I need native ZFS at Blobstore-competitive prices