Android

Not op, but I use it to make automated proper backups of all important apps. Androids own backup system does not catch a lot of stuff, some apps don't support or allow it at all, and it's limited. I just get a full package of all the apps data, every morning, then synced to my nas via syncthing.

I also remove a long list of annoyances:
󠀀- Apps setting brightness (youtube when going fullscreen increases it a bit, some apps do it when showing qr codes (making them hard to scan) ) 󠀀- Make all notifications editeable (The wifi portal ones are anoying in countries that have login websites for all public wifi)
󠀀- Let me screenshot everything
󠀀- Let me downgrade apps and change certificates (e.g. going from a github to fdroid release without reinstall)
󠀀- Apply my vector app-icon pack to systemui, i.e. the app switcher (and app details)
󠀀- Force apps to allow reverse portrait orientations when they inexplicably forbid it (I use reverse portrait while charging sometimes when the charger is behind/above me)
󠀀- Make my notification drawer transparent
󠀀- Mod the home button out of firefox (fennec), and severely mod discord
󠀀- Record calls (my memory is bad, I protocol details afterwards sometimes. Recordings auto-delete after a bit)
󠀀- Remove all drm support from my phone, just in case
󠀀- Let Adaway work in hosts mode, to improve performance and so it doesn't influence an active vpn
󠀀- Morphe modded youtube without its own microg app (while I still have gsm)
󠀀- Lets me select all paths in those app share storage dialogues, so I can make an app save directly to downloads and don't have to make a subfolder for example
󠀀- Make fdroid install just like playstore can, without any forced popups or dialogues, having full system permissions and the ability to downgrade apps.
󠀀- I may have used root to disable the thin gesture bar hint thing at the bottom of the screen in gesture navigation. I don't have it in any case.
󠀀- I also use root to change adb settings on my phone conveniently, like thinner back gesture triggers, using the full 4k resolution of my screen, changing screen locking procedures, hide some icons in my status bar, hide the popup whwn rotating the phone on locked rotation, hide thepopup for screenshots, hide the popup for copy, disable googles play protect scanning and background app killer, change connectivity checker and time server to urls not tracked by google, ... 󠀀- I use root to easily set up and manage a second profile, have my file manager access the entire filesystem inclusing system files, enable the olde GameGuardian (similar to CheatEngine, arguably even more powerful, and for android), and to view and share my wifi passwords regardless of what my specific rom happens to think of that at the moment.
󠀀- I also use it for shizuku, which could work rootless via adb but would be some effort to maintain like that, while for me it's been chugging away for years by itself.