I just don’t see the intrusion.
Firstly, you are syncing your photos to iCloud. It’s equivalent to developing your photos at an old timey film shop.
iCloud happens to have lots of security guarantees, much like the film shop.
But the moment you develop CP, all bets are off. I think most of us lead pampered, selfish lives. Perhaps this is a “think of the children” cry, and perhaps this has been used for many evils over time.
If Apple were to get their lists of hashes from China (a situation they’ve opened themselves up to in the future), then sure, that’s awful. Or if they were doing these checks and alerting law enforcement without iCloud sync, then that’s awful too.
But this doesn’t seem to be a slippery slope, yet. They are targeting a specific case: you uploading your photos, and your photos being of known child sexual abuse.
Yes, there are false positive photos in the database. Maybe there’s even a flower in there. But if you got flagged as a false positive, the moment law enforcement looks at your photos (which, remember, you’ve surrendered to iCloud), you sexually abusing a flower won’t cause any problems.
Or will it? Please, my mind is open. I’d love to change it.