Most people in the US live in urban areas and most travel is not that far. It only takes too long to get places by train because the service is poor and public transit is lacking. You’re never going to take a train coast to coast but it’s be nice to take one from San Francisco to Sacramento, the state capital 75 miles away didn’t end up taking a nearly three hours.
Yes, there’s a new high speed train from Miami to Orlando, but you would have to rent a car when you get to either end anyway because there’s no realistic public transit in all of Florida. By the time you rent a car, you might as well drive around instead of taking the train.
How practical it is will depend on the place. Yes lots of America has been built as suburban sprawl but there are lots of slightly more urban places too where modern regional rail would be a huge improvement over sitting in traffic.
The frustrating thing about living in the bay area is that they ripped up a lot of rail in the 60s and replaced them with roads. Now those roads are clogged and journeys by car take longer than journeys by rail did back then.
