Apropos of nothing, I really don't love the construction of this reassurance. This is not actually a reasoned-through guarantee, it's just two things that happen to be true at the same time. But the latter could change at any point, on-device processing does not preclude the device notifying Apple about what it saw.
https://www.wired.com/story/apple-photo-scanning-csam-commun...
It an interesting place to be in logistically. A very thin line to balance between two very bitter ends.
Same with violence, it's everywhere, but if you punch or slap someone there's huge chance of getting shot or guaranteed jail time.
edit: "This feature, spotted by iDeviceHelp, was originally revealed as part of an expansion of the company's family tools designed for children's Apple accounts."
Pretty clear, this was at least in part designed to prevent child sexual abuse.
I say it's amazing how far we've progressed. We could've prevented an entire Seinfeld episode if cameras could warn the user of the presence of nudity in their photos.