I am used to Waymos and had no worries, but as Addy eventually headed for the sidewalk I noticed the Waymo car never slowed down like most drivers would have with a kid on a scooter in the area. I felt myself getting a little bit mad about it.
This is a really interesting point.
When I'm driving in a residential area and there are kids in the street, I slow down not just to be safer, but also to communicate to everyone around, "Hey, I see the kids in the street and I'm being careful. Don't worry!" I also give cyclists lots of extra room for the same reason — to help them feel safe.
Those Waymo cars probably do see pedestrians and cyclists and are probably perfectly capable of not running into them, but since they're not communicating that fact like a human driver would, it makes people worry. Waymo should fix that!