This doesn't make sense to me. You already have other permissions (draw on top of other apps, full filesystem access, etc) that could be catastrophic to grant t

This doesn't make sense to me. You already have other permissions (draw on top of other apps, full filesystem access, etc) that could be catastrophic to grant to malicious apps. If you don't trust yourself not to grant them, or you don't trust the Android permissions system itself to be implemented correctly, it's already game over. (Edit to add: I agree with everything in your second paragraph.)