When I said "Waymo has been scaling 5x annually" I was talking about paid rides.

clearly the rides are limited by the number of cars

I know, doesn't change anything about what I said. Cars were not the limiting factor. To sustain the 5x growth rate, they will need more cars, which is why there's over 2k in the pipeline and why they've recently built a factory capable of making tens of thousands per year after reaching full capacity.