To be fair, Waymo claims to not record or transmit audio without you either manually engaging such (by requesting support), or a very unambiguous announcement (presumably when the car gets into some sort of emergency situation). And lying about that claim would probably run afoul of California's 2 party consent law. So still a step up in privacy versus having someone in the car listening in on your conversation.

That said, even if they were listening to you, there's a lot of things that are completely inconsequential from a perspective of an anonymous call center employee far away listening in on, that I probably wouldn't want to talk about in front of a taxi driver.