photos/videos and OneDrive: those do get uploaded by “eDrive” if enabled. It has a static folder config of what folders it watches and the sync behaviour isn’t fully 2-way. This with murena having contacts/calendar already is some amount of backup.
I second aibd: use Seedvault (with the d2d option enabled in expert settings) to write to sdcard. Continually transfer that export folder elsewhere. Webdav backup can’t be used with murena atm. Also mind that messengers can have their own internal mechanism.
This isn’t very comfortable I’d agree. But one SV backup is better than none to get restarted.