German trains, as recently as the 90s, were phenomenal, and integrated superbly with the Swiss and others. It is in the 21st century that Germany has gone off the rails.
The Netherlands has a very similar problem: the train system was privatized in the late 90s/early 2000s and has been going downhill since the 2010s or so. While it's still better than Deutsche Bahn, it's just so much worse compared to how it used to be.
German trains were great twenty years ago. I wouldn't be surprised if things went haywire after lockdown. Many things did. It gave people a licence not to work and introduced a sloppiness into everything.