It's perfectly reasonable for me to make a determination and offer my first hand experience about Autopilot's capabilities relative to that of my own and that of other drivers I see on the road.

Accidents might be long-tail phenomenon but driving habits are observable. Autopilot has a consistent, safe, alert demeanor on the road. It reacts to vehicles I as a driver can't as quickly see, changing situations that it would take me an extra half second or more to react to.

Compare that to the average human driver on the road - a third or more of whom you can expect to see holding a phone - and I think it's a reasonable conclusion to say it's already at least marginally better. And if we are talking about accidents, you can't deny that people are generally terrible at choosing the best possible reaction to an emergency situation that happens in the space of a few seconds.