I totally agree. I actually just built some scripts to do this using rclone, but they could easily be modified to work with a remote ZFS which is actually way more ideal. It is encrypted in-flight, and at rest on the remote, and merging block-level increments never require decryption. My key never has to leave my local machine.

https://github.com/jonmon6691/storage_architecture

Tools like Duplicati and Cryptomator also allow this. I'm using Jottacloud, 7,50 EUR for 5 TB (actually 'unlimited' but the speed gets slower after 5 TB). Rclone also has support for Jottacloud. Nice thing about Jottacloud is its hosted on Norway. They got privacy laws there. I know if you encrypt in-flight without having your private key remotely this is far less important, but still. Arguably, these products are therefore competitors.