That's only because they don't drive that fast, and they just dump most problems to a human driver. If a self-driving car stopped in the middle of an intersection and a human driver hit it, the blame would legally fall on the human despite the fact that the self-driving car caused the issue.
Liability of an accident doesn't factor into those statistics. They include all accidents regardless of blame.
And you act like that exact scenario hasn't happened with human drivers. In Arizona alone, 3.5 people die every day in traffic incidents. Given the number of dumb fuck road ragers brake checking other drivers on the road, stopping in the middle of an intersection and getting hit probably happens at least once a day, probably more.
Yet even with all those fatalities, and other accidents in general, the autonomous systems still have fewer incidents per mile driven.
These cars were banned from CA roads because they had too many safety issues. That's why they're in AZ. One company didn't address the issue so the CA DMV threatened to pull their registration completely.
That's an apples to oranges comparison. Self driving cars aren't driving on the same roads and in the same conditions. Maybe they're better, but that hasn't really been tested/evaluated.
They already are, the media just reports on every one of these crashes. Even just reporting on each human fatality daily would put things closer to perspective even with every autonomous accident being reported as if it were the end times.