My question is: is safer than average human good enough?

When I drive I have the option to choose to be safe or not. When a computer drives I lose that option. So for 49% of the people, safer than the average human is less safe than before.

I think we need to reach "Safer than the safest 10% of humans".

Also these reports should be done by a government agency.

From a purely technical perspective, I would expect a Waymo to react to unexpected external stimuli much, much faster than a human. It gives the Waymo options that are unavailable to a human's slower reaction time.

Yes, it's good enough. Because you cannot control who else is on the street around you. Having cars around you that are driving safer than the average is better than them driving average.

You seem to be thinking this is compared to median driver, and not average one: if most accidents are caused by small number of bad drivers, your average will be bad, but even median might still be good.

And this does not even compare the drivers, but simply miles driven.

So I think that 80% of human drivers would likely be safer than Waymo unless they are driving under the influence or extremely tired or distracted.

Note that "13x safer" already implies being in the top 10%, though.