> The main issue with train travel in the US is that many passengers are going to need a car when they reach their destination.
It's not a big issue as you may think. This is the case with air travel too, but people would gladly fly and then rent a car. The biggest barrier is the cost and the time it takes.
Unless you make the trains go 900km/h, you are talking about very different things. “I need to rent a car at the end of this train journey, which itself is about the speed of a car” is dumb — just rent the car, don’t waste money buying a train ticket as well, and travel on your own terms. So the only thing it offers is being cheaper than renting a car for one extra day for long journeys.
I really wanted to take a train or greyhound, wasn't super picky, for my last two trips but it was stupid. I had naively assumed the tradeoff was going to be adding about two days to the trip for travel there and back but in exchange it would be a lot cheaper than a flight. Nope. I guess. For some reason. Same travel days, same destinations. Not only were flights, obviously, faster but they were cheaper too.
Pay more for fewer departure/arrival options and turn a few hour hours into +1 day on each end seemed not worth the vibe.
> So the only thing it offers is being cheaper than renting a car for one extra day for long journeys
Nope. It also offers not having to drive. I can read a book on a train, which I can't do in a small car even if I don't drive because I'll get car sick. I can even walk around and have luch in the train restaurant, go to the bathroom without having to stop.
It depends. It's definitely usually easier to get to your hotel (often by walking) in NYC from Penn than from any of the airports. Less true in Boston (though there is a suburban stop south of the city) and in DC Reagan is pretty convenient on the metro. But, generally, downtown train stations with good transit tilt towards train travel relative to airports an hour out, especially without good transit.
It's not a big issue as you may think. This is the case with air travel too, but people would gladly fly and then rent a car. The biggest barrier is the cost and the time it takes.