ADP sends hashes of the plaintext and filenames to Apple effectively in the clear (non e2ee).

If only you and three other people have a unique file, Apple knows you are a group.

You aren't wrong, but... it's odd coming here to HN and seeing people talk about privacy like we aren't in the nth generation of people trading theirs away for a pittance. I think the market for the sort of privacy envisioned by some here is incredibly small, incredibly niche, and honestly one of the least likely to buy an iPhone in the first place.

Most people broadcast their lives on social media, happily opt in to all sorts of schemes that track them just for minor conveniences. For people like that, the idea that the privacy protection outlined by the OP isn't enough rings really hollow.

Or to put it bluntly, at some point this really stops feeling like a practical debate, and more of an ideological one.

me neither.