I've long expected Waymo's approach to prevail simply because - aside from whether vision-only proves good enough to some standard - it will be easy to lobby for regulations that favor the more conservative approach.
But I also don't think we can take anything from what Waymo claims about the feasibility of vision-only.
Waymo has posted videos of accidents they've avoided purely because their lidar picked up on a pedestrian before their cameras saw anything.
A favorite of mine: https://x.com/dmitri_dolgov/status/1900219562437861685
They're very public about the data that makes them look good, but they went to court to keep their safety data from the public. (https://techcrunch.com/2022/02/22/waymo-to-keep-robotaxi-saf...)
That lawsuit was about trade secrets shared with DMV. And DMV advised them to file a restraining order against a third party seeking redacted info.
It was actually about all kinds of information about the safety of their cars, how the company handles collisions, how they decide to make human drivers take over, details of injuries caused by their cars, etc.
The DMV required them to submit their safety data before allowing the vehicles on the road. Waymo claims that the data the DMV needed about the public safety of their cars, and the emails they exchanged about it with regulators, were entirely "trade secrets" to keep them hidden from the public who understandably felt like they should be able to access that information since those cars are going to be on their streets.
I think past experience shows that the US prefers a wait and see approach - owning in part I think to it federal structure, where states compete for companies good graces and money, so if State A bans something, State B will allow it and gain an advantage in that area.
Moreover, why draw a hard line on vision only when there is existing technology is available to augment it? It's not like they have to develop 3 novel technologies.