They say it’s to stop people from stealing iPhones to sell for parts.
There's an easy fix to this. Allow users to mark their devices as broken/dead in their (icloud?) system, so its parts can be extracted and used for genuine repair. Put it behind 2FA, email confirmation, and require purchase invoice, or whatever to make it happen. To counter edge cases, give a month for appeal, only then mark it safe for usage of its parts on other phones. A trillion dollar company should be able to implement this, but they're trillion dollar company for a reason, so yea...
Thiefs don't have access to the accounts inside a locked phone, let alone the invoice of purchase.
Google claims to do some processing on their own tensor chip locally so it might reduce some data being sent to Google, but it doesn't limit them from tracking you. With Pixel, you are only being tracked by Google and not Samsung or other manufacturer