I did find the Waymos in SF disconcerting as they approached pedestrian crossings while I was waiting - with a human driver there's many different cues that they've seen you and noticed you - whether it be looking directly at you, or slowing down in preparation for you to cross.
I'm sure if I had just started walking across the crossing it would have reacted perfectly, but I wasn't willing - based on the lack of observable "I have noticed you" cues - to test that theory.
That combined with the parent's post is, perhaps counterintuitively, somewhat concerning.
The proper technique for yielding to pedestrians wishing to cross is to start slowing down early, as if you were planning to stop before the crossing. That sends a clear signal to the pedestrian they're good to start crossing. Then you're free to speed back up. This is very comfortable for the pedestrian and the vehicle never needs to stop, so the slowdown is minimal.
That Waymos apparently don't act this way and seem to need to send an explicit signal to pedestrians sounds concerning to me, even if its ultimately safe.
Waymo does slow down as it approaches stop signs (usually where crosswalks are) and it will slow down if there is a pedestrian entering the roadway (crosswalk or not) since it doesn't want to crash into them.
The explicit signal of a driver noticing you (eye contact) is replaced by the signal above the vehicle. Are you not equally concerned that pedestrians have to get an explicit signal from drivers who are legally required to yield or stop??
Ah, so this particular pedestrian crossing wasn't at a stop sign (we were at the big historic army place out by the Golden Gate bridge) so that might explain it.
I'm sure if I had just started walking across the crossing it would have reacted perfectly, but I wasn't willing - based on the lack of observable "I have noticed you" cues - to test that theory.