You seem to be the one going through mental gymastics to justify why the button might not just turn the thing off. Sometimes they’re not out to get you, you know.
These phones cram oodles of stuff into a tiny space at super low margins , and are perfectly good at spying on their users when turned on. There’s no reason for them to spend any extra effort to spy when they’re turned off, for the .01% of people who turn their phones off regularly.
The margins aren’t as low as I thought, but they still aren’t giving any money away on their BOMs…