The regional service sucks to a large part due to a lack of capacity on German main lines. Regional trains and freight trains run at about the same speed, which is great for capacity. However high speed trains are faster and therefore need to overtake them. You need to plan for that, which require additional capacity. In other words, when you take ICE trains of the old main lines, you massivly improve regional rail as well.
I mean I was just ragging on their absolute gobshite regional services, but yeah fair point
The regional service sucks to a large part due to a lack of capacity on German main lines. Regional trains and freight trains run at about the same speed, which is great for capacity. However high speed trains are faster and therefore need to overtake them. You need to plan for that, which require additional capacity. In other words, when you take ICE trains of the old main lines, you massivly improve regional rail as well.