I dunno, I wish Android had a cohesive backup strategy the way iOS does. iPhone is terrible but losing your phone and switching to a new is insanely easy, with all state back to exactly how it was before.
Applications can specify that they can't be backed up, and you as a user have no way of overriding that. Highlights on my smartphone are Fennec (Firefox), Termux, Cromite, Element, Syncthing, various videogames and other utilities.
I absolutely want these backed up, and on any sensible system I'd just point restic to their storage locations and be done. On Android I need an arcane mess of Titanium Backup and TWRP, and god help me if I ever have to recover from a backup.
What is even their motivation to not be backed up?