Isn’t e2ee messaging intended to encrypt data transfer between devices, not provide global security? The default iCloud backups are still encrypted, but the key is stored/recoverable by Apple. This is the ideal sort of encryption for 99%* of the population. For the 1%, an option to forego the Apple stored key is an option.
yes, I made that number up. I will stand by it.
If you did a random survey of users if they want a secure backup, e2ee encrypted, they will say yes. Overwhelmingly. But if you ask the question based on the outcome of a forgotten password: “If you lose or damage your phone and have forgotten your Apple account password, would you like all of your iCloud photos, messages, emails, contacts, and documents to be instantly destroyed and unrecoverable or should Apple be able to restore everything if you can prove it’s your account?” they will almost certainly choose the latter.