I do use ZFS and I just backup the files with restic. To restore a file in a zfs snapshot I would have to download the entire thing to a spare HDD, even if I only need to recover a few files. Restic has snapshots too and is designed to be used with cloud providers like B2.
For my use, it actually cost less to use B2 than the home backup product. The bulk of my data is Linux isos so I’m not really worried about losing it.