The only national passenger train service I know of is Amtrak, which shares its tracks with freight carriers. So the current infrastructure isn’t designed for high-speed rail and freight carriers usually get priority.
Also, The US is really big, so everything isn’t a short train ride away from everything else. If I wanted to visit the Grand Canyon from where I live, it’s over 2,000 miles away. That’s 30 hours of driving just by car.
“Ketamine: Negative” lol.