With its high-speed train, China has achieved what seemed impossible: flying is not profitable on an 808-mile route.
With its high-speed train, China has achieved what seemed impossible: flying is not profitable on an 808-mile route.
evidencenetwork.ca
With its high-speed train, China has achieved what seemed impossible: flying is not profitable on an 808-mile route. - Evidence Network

I would take a 6-hour train ride over a 2-hour flight. Beyond that, e.g. 8-hour train ride vs. 2-hour flight, will have to factor other things.
Exactly, you can have the train station downtown so you don't have to get to the airport, wait for checkin, wait for the plane, etc. If you factor all the time around the trip, 6 hour train ride will win every time.