Remote ZFS replication kinda does. But the offsite backup wouldn't be encrypted and not everyone is using ZFS. So it's not for all situations.
How does it matter if anyone else is using zfs? You either use a service that supports zfs target or run your own Linux instance which is just installing a single package for Ubuntu.
Even for my own use cases, not every server and system I maintain could use ZFS right away.
Still good to know about the encrypted volume feature. Will be sure to test this next year.