That is a dumb analogy. We know a car cannot physically operate in space. Waymo are cars that are designed to operate on roads. It is just a matter of how good they would be.
You don't understand how waymo works. The geofence is an artificial limit. Waymo does not need the geofence to work. They could remove the geofence if they wanted to and the waymo driver would work everywhere. Now, there would likely be some cases that require interventions/disengagements but it would work. We know this to be true because when Waymo wanted to deploy outside the geofence in Chandler, they simply mapped the new area and then deployed there and it worked. When they wanted to deploy in SF, they mapped and deployed. When they wanted to deploy in downtown Phoenix, they just mapped and deployed. And now they have mapped areas of LA and have started testing. Waymo can deploy anywhere. They just map first and then deploy.
In the case of Seattle, Waymo would just map Seattle and then deploy the Waymo Driver in Seattle. Again, we don't know how well it would work in Seattle. There could be situations in Seattle that cause interventions/disengagements. But the Waymo Driver would work in Seattle.