I’ve done overnight Amtrak trips in a “Roomette”. My way of looking at it is the journey is part of the vacation whereas flying is the means to get you where you’re going. A cross country train trip can take a few days requiring multiple overnights. If you factor in what a hotel would cost plusmeals (Amtrak includes two meals a day) then that offsets the cost. Besides that you can carry on drinks and snacks plus you don’t have to pay a fee for luggage. I’ve met a lot of nice people on the train, it’s definitely a more civilized way to travel compared to the airline cattle cars. Though it won’t appeal to everyone It’s more for older people with a lot of spare time that always dreamed of driving across the US.