The data is misleading at best, probably manipulated. Let’s not forget the data is from DB itself.

As an example, in 2018, the then boss of infra at DB, Ronald Pofalla introduced the “Pofalla Wende”, whereby a commuting train between two cities will simply turn around and not serve the rest of the line if it has a certain delay. In itself, one could argue it can make sense under certain circumstances. But all remaining stations on the line are not counted as delays, even if there is not replacement train.

Same with cancellations, these don’t show up as delays.

The situation is significantly more dire than what this data shows.