So, a brief bit of anecdata.
I live in Miami. I’ve been seeing Waymos driving around for the last several months. However, the frequently has sharply increased - and now I see sometimes as many as a half-dozen in a day. Miami is one of Waymo’s “coming soon” markets, so that’s not entirely a surprise - though the density of cars has definitely increased.
Today, though, I saw my first Zoox car - and then two more, later in the day. I had not previously seen any Zoox vehicles, but it looks like they’ve started to roll them out for testing here too.