>This assumes the occasional need for a car

40% of US households have two cars, and more than 20% have three or more [1]. As a two-car household that was able to go down to one after moving to where I could bike to work, I would say your assumption is too binary.

[1] https://transportgeography.org/contents/chapter8/urban-trans...

The thread started out as Europeans being sad about missing out on driverless cars. In e.g. Berlin, about half the households have zero cars.