While nothing affects me personally (always been an AOSP user via Lineage/Cyanogen), I know that at least some apps struggle with vendor "enhancements" that go counter to what users want. DAVx5 (CalDAV/CardDAV sync) is one I remember having warnings about OnePlus (2nd worst here) during setup and how you need to take extra steps to ensure syncing actually works, which is pretty important for such an app. On vanilla,…
I followed the steps suggested in the setup and it works just fine now. I'd much rather have a complicated opt-in to background activity than any form of opt-out.