How do you upgrade brake pads over the air? Or ensure tyre and wheel conditions? Or any of the other mechanical parts of the car (suspension, axles, transmission in-so-much-it's-still used...) Or ensure sensors are not interfered with? As soon as you get Waymo into private hands (or competitors need to cut corners), you'll start having issues like these.

I don't think hoping for self-driving cars is stupid, and I would certainly love to have one I can trust to take me and my family around safely. But to get to that trust, I want better reporting than what this study provides and proposes :)