Passenger railways make sense in places where one metropolis is close to another, and to yet another, etc, with suburbs commuting to these cities, too. This is what you see in Europe like Germany / Netherlands / France, this is what you see in central Japan, this is what you see in coastal China; all these places have very high population density, It works to an extent in US Northeast. All these places have dense and working passenger railways.

But they are a major investment that needs to be repaid, so they need a lot of use. I don't think I'd pay twice as much to get from NYC to Philadelphia twice as fast (say, 45 minutes instead of 90-100), and even 4 times as fast (say, 20 minutes). It would cost comparable to hiring an small airplane already, because there's no such a mass daily ridership. And most places in the US are much lower density. Airplanes are more economical over large sparse spaces.