Imagine taking a photo or have in your gallery a photo a dear leader doesn't want to spread. Ten minutes later there's a knock at your door.
Imagine now a young child being sexually abused in front of a camera for all its years of existence, and that there's no knock on the door.
Yet the privacy implications will last forever. Once it's implemented, it only takes a rubber-stamp warrant to compel Apple to scan your device for anything the government deems concerning. In fact, no warrant needed in most countries.