Good question. We know that Waymo has about one remote operator/customer service rep per 40 vehicles. Waymo also operates vehicle garages for charging, cleaning, and maintenance. Those probably all add up to roughly what it costs a rental car company to operate a car. Maybe more, because there's more complex maintenance, maybe less, because they park themselves.
There's also a huge sunk R&D cost and an ongoing R&D cost that probably dwarfs operating costs. But the per-car cost drops as more cars are deployed.
On the other hand, robot vehicles can have higher utilization than single-owner vehicles. They can be on the road as long as there are customers. Observation of their parking lots indicates most of the cars are out on the road about 12 hours a day.
There's also a huge sunk R&D cost and an ongoing R&D cost that probably dwarfs operating costs. But the per-car cost drops as more cars are deployed.
On the other hand, robot vehicles can have higher utilization than single-owner vehicles. They can be on the road as long as there are customers. Observation of their parking lots indicates most of the cars are out on the road about 12 hours a day.