If you want a more baseline approach: I am backing up all of my servers and my Linux work laptop using my own rsync-based backup script: Hactar
EE2E encryption is not a feature of the script but merely a consequence of the environment around it. Transfer typically goes over encrypted SSH connections and storage lives - in my case - on LUKS encrypted volumes.
The neat thing about this method is that it uses rsync's "linkdest" functionality, which hard-links all files to a target dir (the previous' days directory in this case). So each backup is a full copy of all files, but the whole backup only stores one copy for each file (hard links are just multiple references to the same inode on disk), so storage only grows by the amount each day.