Again, I don't see how that is supposed to work. How long are people going to pay attention to "the big picture" when they still are only very rarely required to do something? If they don't have to do some action to actually keep the car on the road or to avoid getting honked at every 30 seconds or so, their minds will drift off.

This is just regular human nature. Sure you can do it for a while, but after a while you stop doing it.

I am quite sure that Tesla et al will discover soon enough you can't rely on people to step in like that. They just need to get their cars to work better than humans, all the time. (or as Elon Musk said, they should be at least an order of magnitude safer)