Excellent observation!
A thought occurs to me. Let’s say that we do the same thing here in the U.S. What flights would be considered non-regional? Would it be based on time in the air or on ground distance by road?
Also what about the TSA? Wouldn’t they by necessity have to set up shop in “every” train station in the U.S. Imagine the jobs created by that..... Imagine the headaches of casual travelers.