Consider this as it scales up, though - I can get electricity from anywhere for my car, from a 120V socket in front of a building that a nice owner lets me borrow for an hour, to a 600VDC superfast charger. I can get gasoline anywhere. Heck, there are even hydrogen stations around here now.

I just don't see this kind of thing being scalable to anything other than small urban areas, which are exactly the place they're not needed, because you can charge a car with 300-400km battery range once a week or less and be fine in the city. Where I need my battery swap is more likely to be while I'm on a road trip going for distance. How could I be confident a full battery that's compatible with my car is going to be available for me, and that all the automation to replace it will be in perfect shape, and that the bottom of my car hasn't rusted to the point where this doesn't work anymore?