Or Google and GM have the data, but aren't sharing it because people will overreact because despite it being an order of magnitude safer than human drivers, it still has some incidents that people will focus in on.
All of this accident data is publicly available with details about every accident. For example, Waymo had four accidents in May and four accidents in June.
[1] https://www.dmv.ca.gov/portal/vehicle-industry-services/auto....
There is no way to truly evaluate safety being an order of magnitude better until we have 1 billion miles driven.
You can crash less often (reduce fender benders) but kill more people (have rare but egregious errors) so I am not interested in seeing statistics about incidents or collisions.