Arguable. For every London in Europe, there’s 10 cities that grew 3-5-10x since 1945. After all, the postwar boom happened on both sides of the Atlantic. London, Paris, etc. are outliers.

It was just policy decisions in many cases.

To a large extent it’s about path dependency as well. You simply aren’t going to fit car infrastructure in a dense urban area whose streets were originally made for horses and pedestrians. It’s not like several European cities didn’t try though, in the heyday of car-oriented urban planning from the 50s to the 70s. Insofar as those attempts succeeded they are now being undone in favor of transit and walkability.

I don't understand this argument. The automobile is much younger than the country. Cars became broadly used about a century ago, the 1910s-20s. How many U.S. cities do you imagine there are that were created after that? Or even that, due to cars, dramatically changed their size relative to the overall population?

>>I recently came back from a visit to London, and did not once need a car

Well, to be fair, if you are talking about a specific city in Europe then you should do the same here in the USA. London's american equivalent is NYC. You will not need a car here either.

>I recently came back from a visit to London, and did not once need a car

I'm not sure this is a great test. (Though, yes, London does have a great transit system even though I've also taken cabs from time to time for various reasons.)

When I visit American cities and don't travel outside them, I very rarely rent a car and don't necessarily take cabs/Lyfts all that much other than getting from the airport. I'm usually staying/doing business in/eating in a relatively central location that often exists in cities that are otherwise fairly spread out.

To give just an example that I'm very familiar with. I never rent a car any longer when I visit Raleigh but I'd never claim you could live there without a car.

Historical note: most US cities had dense public transit until the rise of the automobile. Those transit systems were bought by the car companies and dismantled to drive adoption of private cars. A similar path led to the creation of the crime of 'jaywalking' and getting people off of the streets so car adoption wouldn't be stopped by high rates of drivers killing pedestrians.