People always say stuff like this, but plenty of European cities like Utrecht have shown that it's very much possible to turn the tide. A few years ago Utrecht replaced an entire highway and turned it (back) into a canal and the area is indescribably nicer in every way, it's called the Catharijnesingel.

This canal was, in fact, always there, they just turned it into a highway at some point in the 70s. So the reverse is more than possible, it's a question of will to do so and convincing the, frankly, selfish car drivers. Having lived in the US myself for a stint, there's plenty of cities that could easily have work done similar to what happened in Utrecht, it's just that there's a lack of a will to do so to make things much better.

Sure, you won't have a direct train from NYC to Dallas (although, seeing China's high speed rail I don't see why that couldn't be on the table), but we're talking about individual cities making these changes a bit at a time.