This seems like an over-reaction. I'm highly opposed to Apple's CSAM move but they are still much better and transparent than Google, Amazon, and most other services.
Many of these already do something like this but they just don't actively tell you or document it.
Also, and please correct me if I am mistaken, Apple's CSAM is limited to iCloud for Photos. It does not just work against your local photos.
CSAM Detection enables Apple to accurately
identify and report iCloud users who store
known Child Sexual Abuse Material (CSAM)
in their iCloud Photos accounts
It seems like a needless waste of time do do all this as opposed to disabling iCloud for Photos...
Source: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...