Pretty sure most things are stored encrypted/delivered encrypted only to be decrypted and rendered on your phone. Meaning Apple/your provider have nothing to give up for the hypothetical US government demand.
To add to the other comment, Apple installed on-device scanning to iOS as far back as version 14.3 (https://pocketnow.com/neuralhash-code-found-in-ios-14-3-appl...). They claim they won't activate it without a court or government order, but these are becoming easier and easier to obtain. Under the Patriot Act, virtually anyone's electronic devices may be searched for any reason. In effect this means that Apple has access to all information on all iOS devices, and the government may access any of these at will.
“iCloud Data Recovery Service
If you forget your password or device passcode, iCloud Data Recovery Service can help you decrypt your data so you can regain access to your photos, notes, documents, device backups, and more. Data types that are protected by end-to-end encryption—such as your Keychain, Messages, Screen Time, and Health data—are not accessible via iCloud Data Recovery Service. Your device passcodes, which only you know, are required to decrypt and access them. Only you can access this information, and only on devices where you're signed in to iCloud.”
