Borg is an interesting backup utility that runs from the command line. It runs of macOS and Linux, and possibly Windows.
Vorta is a GUI-based backup utility that uses Borg as the backend. Vorta runs on macOS, Linux, and Windows.
BorgWeb is a webserver that implements a browser-based front end for the basic functionality of Borg.
I have Borg and Vorta on my ‘to try’ list, but haven’t tried them yet.
Borg supports seemingly everything one would need in a backup (probably not bootable), including encryption, of course.
Borg does deduplication when backing up, and does this at the block level. So if you’re backing up three computers and they all have the video of Aunt Martha’s wedding, only one copy will be saved on your backup device. If you edit part of the video and the rest doesn’t change, only that block will be backed up in your next backup.
Borg seems to scratch the itches that several users have had for Arq, but which have not been implemented.