The changes here are not just security but privacy related - new Androids now have permissions like "only allow location while the app is open", which was loudly requested even in HN community (and rightfully so).
This does mean that apps now need to take such new features into account and not horribly crash when users want to use them on the phone.
Requesting compliance with all new privacy features on Android 9,10,11 is not unreasonable for a store IMO. Especially when sideloading exists.
For privacy violations I think delisting is reasonable otherwise everyone just ignores it. We developers usually get more than a year of warning to fix the apps which hasn't been too onerous.
This does mean that apps now need to take such new features into account and not horribly crash when users want to use them on the phone.
Requesting compliance with all new privacy features on Android 9,10,11 is not unreasonable for a store IMO. Especially when sideloading exists.