My expectation (from what I know of Waymo's current behavior) is that cars will be perfectly safe and predictable road citizens, no more threatening or dangerous than a Roomba.
There is a reason city drivers are aggressive, and it’s not just because they’re stressed out. It’s literally necessary to make any forward progress in many cases.
When the cows don’t behave, it’s because they aren’t spherical enough.
Good luck with that. It works, to some degree, when you can control all the variables.
Good luck with that approach when you’re dealing with NYC pedestrians, or Midwest winters, or cyclones/hurricanes, or auto rickshaws, etc. etc.