If you want your photos to upload in the background, iCloud Photos is your only choice on iOS. Not so on Android. This makes backing up photos to a server privately on iOS essentially unusable.

This kind of crippling anti-privacy pro-Apple-profits design permeates iOS. You cannot even install an app on your device without giving Apple your billing details and letting them know you installed it, which is used for ads. You cannot get your location without also telling it to Apple. You cannot tell Apple not to track your WiFi SSID's location. You cannot uninstall Apple News, which is filled with user tracking for ads. On and on.

> We recently had a thread from a historian whose entire account was suspended after Google scanned all the files in his Google Drive,

You're comparing iOS to the wrong entity when you compare it to Google instead of Android, but even your comparison to Google is faulty. Your link is about Google suspending an account for files shared publicly, not about Google scanning all the files in that account. Section V.B. of https://www.apple.com/legal/internet-services/icloud/ says that sharing those types of images publicly is also a violation of the iCloud TOS, and Apple has the right to do the same thing. The difference is that Apple will probably handle the customer complaint better, but that is an issue of customer service, not privacy.