They specifically referred to it as a "waymo". Everyone wouldn't own one, they would hire one for the trip, like you can already do with a non-autonomous rental car for a cross-country trip.
Own or rent one, doesn’t matter, my point still stands. Access vans, busses, trains, plains, etc. are all technology which exists. Worst case your state can subsidize you a hired assistant with a drivers license who can do the driving. These are all technologies which exist today, and are available to mobility impaired individuals in many parts of the world. Only extremely limited areas have a "waymo" available and only for a limited number of trips. The former can be implemented as soon as there is a political will (and already has been implemented in many parts of the world) while the latter requires faith in a technology that does not exist yet.