Before the travesty flying has turned into domestic flying wasn’t a thing in Germany too. Every car maker from cheap to the luxury ones traditionally offered hot-rod v8 station wagons. The main purpose for it was to replace short to mediul haul flying.
The arrival in the 1990s of the cheap discount tickets and cheaper airlines....really bulked up in-country flights. A flight from Hamburg to Munich is roughly $110 (in the non-tourist season), round-trip. From Berlin to Munich, it’s $85 round-trip.