Most app data you cannot back up easily without root anymore. I used to use Titanium but stuff stopped working consistently even with root.

Settings and some apps aside, I otherwise basically do this myself. I keep my last model phone as the fallback and use Syncthing to copy pictures, SMS and call log exports, TOTP exports, Signal backups, and any other useful files automatically to it. Contacts and everything else is cloud already. Would take about 10 minutes to reimport and start using.