Given what I've heard about the secure enclave on the iPhone in the last year or two, you'd hope Apple could get something as basic as the webcam light right.

I'd imagine it's feasible to have the LED and the webcam on the same circuit, so you can't power one without the other (disclaimer: not an electrical engineer). Honestly I'm not sure why you ever _wouldn't_ do it this way -- having to control the LED from software sounds like unnecessary complexity to me.