Every cloud service that holds your photos in a non-e2ee way (read: Google, FB, et. Al.) scans your photos. They’re all afraid of the .gov accusing them of holding illegal content.
I can relate to that, for sure. I also dislike the idea of having my personal property used to spy on me. The battery impact, the potentially degraded performance, and the overall creep factor. I dislike it all.
However, that was not what the parent stated. They said "Apple scan your photos.", to which I replied everyone else does as well. Because they do.