I have my whole unraid server backed up using Backblaze's windows backup tool / subscription.

There is a docker container for running the backup app, so it can be setup on a standard Linux desktop as well I believe. You just need to mount the storage you want backed up into the container as another drive and then you can configure the backup software in the fake window environment to back up those drives on "your PC" in the container.

I looked into Backblaze but for my use case rclone + deep archive was less than half the price and about the same work to set up for my home server.

I've got 20 plus TB that I'm backing up, so the costs work out in the other direction for me.