Tesla does have a sensor in the wheel that "feels" for resistance on the wheel. In my experience, it's more than sensitive enough to be able to detect a hand being on the wheel, but is easily defeated by idiots.
I'd imagine Tesla wasn't thinking about how the driver alertness feature could be countered unfortunately. Perhaps we'll see Tesla adapting the eye tracking tech that Cadillac Hypercruise is using.
Never knew about the Cadillac. Very cool, thanks for calling it out.
I wonder how to truly tell if a driver is attentive? The Cadillac indicates it uses head tracking technology. I wonder if that is sufficient? Seems you probably need even eye-tracking: an attentive driver keeps looking around or something.