The way this will manifest is the drunk idiot who'll puke all over the car. The bored asshole who carves his initials in the seat. The edgelord who gets their jollies out of destroying other people's stuff.
Good chance you had some in the original group as well, but early adopters are usually mostly people who deeply understand tech. Once that falls away, you have a less thorough understanding of tech, and a very surprised realization that booking something under your name that has cameras all over will likely result in you being held accountable for what you did. But after you did it.
How that'll play out in the long run is anyone's guess. If Waymo maintains rigorous enforcement and the courts actually play along, it might just work out. It's still going to be capital-intensive because we seem to have created a world where being a major asshole in public without consequences is kind of an entitlement people expect to have, and Waymo will need a very strong "yeah, not here" vibe to prevent that. Which requires a number of high-profile incidents.
Yes, the subtext of the question likely was "are you discriminating against the poor!?" If it was indeed, the answer to that question is "no, the ride pricing will do that".