(Keep in mind that picture was taken when the US has 58 million less people or 17% smaller than today)
But we also have to understand that the US continent could grow to a billion people and still only have the density of France. That is not a matter of lack of land, its a matter of political will.
There have been attempts to push this idea: https://ui.charlotte.edu/story/why-not-1-billion-americans-o...
Anyway given that the land is sparsely populated it is still a fair comparison: When you have such a small population but access to such abundant resources that few others have on the planet, you are going to end up in a scenario like what the US has now.
Here's a map of it; see how densely it links up this vast country: https://vizettes.com/kt/rta/maps/usa-rr-1920.gif
Meanwhile, the Netherlands was completely car centric just like the USA until the 1990s, when they decided to start redesigning roads to prioritize walking and cycling. Are you sure these things are really inexorably linked to geography?
People in Europe dont take a train from Greece to Sweden. They fly. In fact most fly Vienna to Amsterdam.
In the same way somebody from New York would definitely fly to LA. (They are not driving now btw)
That doesn't preclude the existence of public transport connecting NY to Philadelphia. It also does not preclude NY from being walkable! Or bikeable. It doesn't stop NY from having good public transport! It doesn't force you to drive to work in NY.
This is much more about local policy.
Different solutions at different scales!