A normal car with normal cruise control does not keep itself in a lane. Nor does it adjust for the speed of other cars. All it does is make your speed a constant; you still have to steer and initiate any and all braking or overtaking maneuvers.

Some do adjust speed. The point being, neither is a fully automated auto-pilot - the human behind the wheel is always responsible for stopping the vehicle or steering away from obstacles in an emergency.

Perceptually it's very different. And it's perception that matters a whole lot here, unfortunately.