> sure it is comfy but compared to a plane
A large part of the comfort factor is that a direct train takes me from city center to city center, while a "direct" flight requires me to first get to the airport, then navigate the airport, then get from the destination airport to the city. That not only easily adds at least 2 hours to the trip (30 min x 2 spent getting to/from the airport, 30 minutes to get through the airport/security in the best case, 30 minutes to be there at the boarding time), you also spend at least half of the time actively having to do something.
A 4 hour train vs. a 1 hour flight? The flight shaves off one hour of wall-clock time at best, at the cost of being a lot more hassle. But you don't think about this when booking, nor about the luggage surcharge etc. You see "4:00" vs. "1:07" and "$99" vs. "$29".