Two weeks ago I traveled to Antwerpen from Nuremberg in Bavaria and back in three days. A plane might have saved me three hours in real time, but that is not worth the carbon emission or the lack of "place" for me.
Of course I would't take a 40 hour train trip to Portugal, but I took a one day trip from our home to Bordeaux with two small kids and that worked quite brilliant.
Next week I will go by sleeper train to Neapel, visit Pompeii stay for a night and go back by sleeper train.
I don't know, it has it's problems and there are a lot of things that go wrong but it also has feeling of "place" of change. Even on business trips I don't have the feeling of somehow switching between arbitrary grey meeting rooms with a plane.
I think there are a lot of things that can become better but the international lines have already become much better in the last years and one reason is just that you have Apps to navigate any kind of public transport.