Let's suppose Waymo's fully automated stuff has tenfold-fewer fatal collisions than a human. There's no way to avoid the fatal accidents a human causes, and the solution to Waymos getting stuck sometimes is simple. The point is that the Waymo can actually be described as superior to a human driver, and the fact that its errors can be corrected with review is a feature and not a bug - they optimize for those kinds of errors rather than unrecoverable ones.