I would have thought this as well. Looking at a trip from Fukuoka to Tokyo though. Shinkansen takes 5 hours and costs about $200. An economy flight is around $50 and takes less than 2 hours, although it’s possible there’s a lot more overhead to that time.
While economical in the sense of a personal budget, airplanes are not nearly as economical as high speed rail in general.
Subsidies and externalities kind of muddy the water when it comes to ticket prices. While it is generally cheaper to fly, this is because you are not paying for the damage your flight is causing to the city around it. Noise, pollution, damage to property, and disruption of the quiet enjoyment of those around you.
Shinkansen is a for profit business that acts as an engine to turn worthless rural land into extremely valuable land. Air travel does the opposite. Property values around airports are extremely low. Every plane rattling people's windows and dropping a plume of unburnt fuel and exhaust on people's heads damages the area under it.
I don’t know if there’s really that much time overhead. If I’m spending $200 on that rail ticket, I’m gonna arrive at the train station early to account for any issues I have getting there, just like an airport. I find it a little frustrating that people argue that there is zero time overhead in getting to a train station but there’s like three hours with an airplane when in fact, it’s often two hours for airlines and one for trains in reality.
For flights you have to go through significant amounts of security which is often highly variable.
Further, flights tend to be distinct events. For many routes there may only be one per day, and even for busier routes you usually can't just hop on the next one without significant effects on your travel plans, for example rescheduling connecting flights. Trains on the other hand just keep running, there's going to be another one going the exact same route every few hours at most, likely less for busy routes. You can go to a train station without looking at the schedule, for a flight you're scheduling your entire day around it.
