Android breaks the API regularly by changing the permission game.
The PSF has limited resources (3 million of dollar of budget) to exists (this includes running pypi and organising pyconf), but I think it's track record is quite good, even comparing to commercial products.
It's not that simple.
The targetSdkVersion says what you designed against. If you claim supporting the new API, you should handle the new API (and that includes detecting what the underlying device supports). That does not preclude you from including the support library needed for lower API levels still supported.
"2019 onwards: Each year the targetSdkVersion requirement will advance. Within one year following each Android dessert release, new apps and app updates will need to target the corresponding API level or higher."
https://android-developers.googleblog.com/2017/12/improving-...