Could be because Uber or Taxi is trying to make most trips and maximize day earning while Waymo do not have that rush and can take things slow…
Of course Waymo needs money but if the car made fewer trips compared to Uber/Taxi, it is not suffering the same consequences.
We need to consider human factor and the severe lacking of that in these robot/self driving/LLM and drawing parallels is not a direction I am feeling comfortable.
End of the day, Tesla also sold half baked self drive that killed people, we should not forget.