Nothing stops Apple from offering e2ee backups, and in fact they do this for certain data backed up to iCloud (health data for example.)
But your iMessage data...well there, your ass is hanging out in the breeze. In fact, I'm not sure it's possible to log into an iPhone with your Apple ID and not have an iCloud backup immediately fire off, which means your private encryption keys hit iCloud and stay there until it is purged according to their data retention policies. And we have no idea what those policies actually are; those keys made end up stored forever.
> Nothing stops Apple from offering e2ee backups, and in fact they do this for certain data backed up to iCloud (health data for example.)
Almost all users can't handle this; to support people, you need to be able to recover their account when they've lost every single password and proof of identity they possibly can. It's not a backup if you can't restore it.
> In fact, I'm not sure it's possible to log into an iPhone with your Apple ID and not have an iCloud backup immediately fire off
You are correct there’s a bit of dark pattern going on here, but it is possible (to the extent the code does what it says of course). To be extra sure I have a custom lockdown MDM profile to disallow iCloud backups, as well as a number of other nefarious things like analytics, and whenever I get a new device, I first DFU restore it to the latest iOS image to ensure software (post bootrom) isn’t tampered with, then activate and install the MDM profile via a Mac and only then I interact with the device and go through setup.
But your iMessage data...well there, your ass is hanging out in the breeze. In fact, I'm not sure it's possible to log into an iPhone with your Apple ID and not have an iCloud backup immediately fire off, which means your private encryption keys hit iCloud and stay there until it is purged according to their data retention policies. And we have no idea what those policies actually are; those keys made end up stored forever.