That WW2 theory seems like a bit of an odd take, although not a completely outlandish one. I also noticed that in the late 19th century, railways received a lot

That WW2 theory seems like a bit of an odd take, although not a completely outlandish one. I also noticed that in the late 19th century, railways received a lot of government support and that is what enabled a dense network of passenger train stations in city centers in the first place. At least in Germany, there are options to bring the cost of long distance train tickets down considerably. Booking far enough in advance can get you almost any long distance ticket to proces comparable with flying. If you do that a 3 or 4 times a year, consider getting a Bahncard 25, which is a cheap 25% off coupon for a year. It just needs a few train rides to completely amortize. Just don't forget to cancel it in time when you no longer need it (that's the catch). I don't know if other countries have similar options and how effective they are.