Why are the train carriages on some trains, such as regional trains, coupled in the middle of the route and not at the starting station?

ByBeantyLombers32

Hello, I have often noticed when I travel with the ÖBB (Austrian Federal Railways) on the regional train (Cityjet) towards Vienna that, especially on weekdays (during working hours), train carriages are coupled in the next largest town, a major city in the state capital of Lower Austria, for example (approximately halfway along the route) (where…

Would you ever have thought that you could travel these train routes with the regional train with only one or no changes?

Bylcld1403

For example, these train routes: Düsseldorf-Hannover 1 change Düsseldorf-Paderborn 0 changes Mainz-Cologne 0 changes Frankfurt-Cologne 1 change Can you think of any other train routes like this with only 1 or 0 changes where nobody thinks this is really possible?