Technology and time are not static but constantly progress. It has been said, "Fear God and Time." A more contemporary phrasing might be, "Fear God, Time and Technology"!
History, including railroad history, is a valuable source of knowledge, from which we should take/learn valuable lessons from as we inevitably progress forward.
Early on, there was Horse and Mule power, then steam locomotives and then dieselization; and, almost certainly some form(s) of non-fossil power is just around the bend.
My point is we are fortunate to have "765 - the 21st Century Survivor" [Thank you, Rich] , and other steam power still on the rails; plus numerous static survivors of the "Age of Steam."
More importantly, Each of us also has our personal "time travel machine" .... in the form of our train layouts and collections ... both big ones and not-so-big ones.