Insurance for human drivers stays the same. If anything, it goes down, because the more Waymo-level autonomous vehicles on the road, the safer it is overall.

Insurance isn't a zero sum game, where "less insurance spent on autonomous vehicles" means the insurance companies have to make up for it somewhere else.

In a way, "car driving getting safer overall" isn't great for car insurers, because they make money financing auto risk, and if there is 50% less auto risk then they have less addressable market.