Multiple factors: market viability, climate compatibility, capacity, and definitely regulatory factors. Currently DC, NYC, Boston and Chicago are all being slowed down by anti-Waymo groups like Uber drivers and public-transit lobbyists.
Waymo is a sort of public transit. It's just an vastly more inefficient than any other form of public transit, but an order of magnitude more efficient than private passenger cars.
Waymo is a sort of public transit. It's just an vastly more inefficient than any other form of public transit, but an order of magnitude more efficient than private passenger cars.