That's one more of those "irrational exuberance" regarding the future of autonomous driving. It would never even come close to being legal if it's only better than the average driver. It will need to be better than the 95th percentile of human drivers at the very least. 48% of the human population are not going to accept a more dangerous, potentially deadlier, car ride because it's "safer on average".
I'm just spitballin' here, but perhaps they could make something that was better than the average driver, and wouldn't swerve or accelerate into stationary objects like highway barriers? That sounds like something a lot of people would want.