I spent a year in Germany circa 1999 and then overnight trains were all the rage. For instance, Dresden to
Amsterdam was an easy and inexpensive trip. Going east you
could get to Budapest, going south to Innsbruck, etc.
At that point an American in Europe would ride the train as much as he could, but the Europeans I knew thought taking a plane was cooler and it was a good experience because the plane had competition from the train.