There's one case I know of where previously working behavior is broken, for something which was not an abuse vector at all: if your app depends on the hardware

There's one case I know of where previously working behavior is broken, for something which was not an abuse vector at all: if your app depends on the hardware "menu" button (which is the case for nearly all apps made back when having a hardware "menu" button was standard for Android), for several versions Android showed an emulated software "menu" button next to the back/home/etc buttons, but more recent Android versions no longer show that button, breaking all these apps (since there's no way to get to their menu). See https://www.xda-developers.com/rip-menu-button-android-10-drops-legacy-support-extremely-old-apps/ https://www.xda-developers.com/rip-menu-button-android-10-dr... for details.