Indeed, when comparing trains to airplanes, the time necessary to get from the city to the airport and the security checks & boarding time are generally forgott

Indeed, when comparing trains to airplanes, the time necessary to get from the city to the airport and the security checks & boarding time are generally forgotten (repeat at arrival). It's generally around 1 to 3 hours for a single flight. So, for a short flight, using the train may take the same time than using the plane (particularly true in Europe with the speed trains). For example, Paris-Frankfurt, next wednesday with Deutsche Bahn ICE 9553 it's 4 hours for 56€ from city center to city center (cheapest price for the week, it can go up to 350€). By plane, with Air-France it's 1h20 from airport (CDG) to airport (FRA) for 127€ the same day. From Paris center to CDG airport, it's around 30 mins, and for Frankfurt airport to Frankfurt center it's 40 minutes. Both ride by local trains (for 5~10€ each). All in all around 2h30 from city-center to city-center, but then you need to not forget the necessary time for security check & boarding. Let's say 1h30 only because you have no luggage... If you have a luggage add 40 minutes more. All in all, for this ride, the time is around the same, but the stress is not...