There is also the monetary angle. How many european households can afford a car for both parents and a car each for two kids, registered, insured, paid for to park wherever they go?

Even if you are poor in the US cars are remarkably accessible. You can finance a used car with no credit and a couple dozen dollars a month.

And the parking angle.

Europe builds apartment complexes which are ~3 to ~10 stories tall, the US builds sprawling suburbs, zoned so that there's no grocery store in sight.

If you're packed 3 to an apartment in a 10-story complex, it's unlikely there's enough parking for all of you.