The best use case for oneself would be if missing features are emulated with dummy data using some app-firewall tool. The phone should give any app no chance of

The best use case for oneself would be if missing features are emulated with dummy data using some app-firewall tool. The phone should give any app no chance of finding out, whether e.g. address book access was granted, but instead show fake data. Of course this would soon be a cat and mouse game if Google really implemented it for everyone: Developers like WhatsApp would check the address book data whether it is statistically sound and if not they would request you to grand access for real, etc. All the permissions only required for ads (like position, IMEI, full internet access, reading sms, reading address books) would also just have the app terminate if it's not possible, just like today they check for rooted devices based on tools like bash or they check for modified hosts files that block ads.