Deja-Dup is our backup tool - it is well maintained by GNOME. The next version is libadwaita though.
There seems to be a real lack of choices in the repo - need something that covers both adhoc and scheduled backups - to both local and cloud providers.
… and TimeShift is not a backup tool for local stuff.
This is one area we need to carefully consider - for the moment this is one libadwaita app that we may carry forward.