Trains are directly linked to capitalism, not sure what you are getting at here. They require incredible amounts of capital to build, and incredible amounts of money to operate. They enabled the industrialization.
Communist countries also, in fact, received their trains from capitalist countries. Russia had hardly any before the US started supplying them during the industrialization process by Albert Kahn and associates.
The most train centric countries in the world are also the most capitalist. Whether that’s state run capitalism or private, state run generally provides more passenger rail service. However, Japan is an exception there with its JR Rail.