I wish USA wasnt so far behind a lot of countries in transportation. USA really ****ed up catering to cars over everything else. Even here in China I can get to every major city pretty fast on a high speed train. Trains going 200-300 mph is a great way to get around. Plus you can get all sorts of food, bring whatever on and walk around, oh and they all have good wifi or 4g/5g connections. I prefer it to flying unless the time is a lot longer. The price is usually pretty reasonable. Even the business class tickets where you can lay down and reasonable. They do have the slow sleeper type trains, but who on earth wants to take that length of trip?
I dont know why you would ever take the train in the USA except to experience being on a train. But just go ride the Heber Creeper or something. Rent a car if you dont want to fly, its so cheap and way faster than a train. Plus you have a car to get around in when you are there. That will also save you money over flying/train.