If your core concern is privacy, surely you'd be fine with "no bytes ever leave my device". But that's a big-hammer way to ensure no one sees your private data. What about external (iCloud/general cloud) storage? That's pretty useful, and if all your data is encrypted in such a way that only you can read it, would you consider that private? If done properly, I would say that meets the goal.

What if, in addition to storage, I'd like to use some form of cloud compute on my data? If my device preprocesses/anonymizes my data, and the server involved uses homomorphic encryption so that it also can't read my data, is that not also good enough? It's frustrating to see how much above and beyond Apple has taken this simple service to actually preserve user privacy.

I get that enabling things by default triggers some old wounds. But I can understand the argument that it's okay to enable off-device use of personal data IF it's completely anonymous and privacy preserving. That actually seems very reasonable. None of the other mega-tech companies come close to this standard.