Is this an old article? They haven't consistently run on time for around a decade. The service is no better than supposedly worse trains in say the UK and is nowhere near say Korea's train system.
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.