As far as I remember, Apple's proposal was to involve https://en.m.wikipedia.org/wiki/Perceptual_hashing https://en.m.wikipedia.org/wiki/Perceptual_hashing whic

As far as I remember, Apple's proposal was to involve https://en.m.wikipedia.org/wiki/Perceptual_hashing https://en.m.wikipedia.org/wiki/Perceptual_hashing which is meant to sidestep this exact problem - and either way, your objection would be equally applicable to CSAM. There is no mechanism that works better for it than for copyright enforcement.