Some parties like Apple have decided to scan photos from your device for illegal material.

No they haven’t, they aren’t, and they never even discussed scanning your messages like that. There’s a communication safety feature available to enable in parental controls so that if a child’s phone locally recognizes (using machine learning) that they received or are about to send a nude photo, the receiving photo is blurred and they’re given information about making safe choices and then allowed to continue or not.