It seems apple devices are a black opaque box: support.apple.com/en-us/HT202303 Every thing is encrypted except imap email storage. They have no access to anything except that. They can't do anyting with any data except imap emails stored on their server.

The governments want them to do some thing preventing CSAM, so now they can match a perceptual hash--not content--to known images from an non-governmental organization. That is about the minimum invasive CSAM prevention anybody can do.

Can someone suggest an alternative CSAM prevention which is less intrusive?

It seems the alternative would be to continue to be a black opaque box, or NOT encrypt you photos and rumage through them.