There is no such thing. Most things in Germany generally are delayed. Wether it's construction projects, really ANY construction from an autobahn local repair to a house to large projects like BER airport or Stuttgart 21 or Zweite Stammstrecke in Munich to literally every Deutsche Bahn ride.

I've been on a Deutsche Bahn train for the first time in two decades when I visited Germany again last week. I had a short regional connection on an Regional Express train (RE) to make it to the 'high speed' ICE train. The RE train was 56 mins delayed or my generous 24 min connection. So I had to be driven by car instead to make it. The ICE 'high speed' train never hit more than 160kph and that only for minutes. A long time it was slowly creeping along at 40-50kph. My (on-time departure) 2 hour ICE train got me into Frankfurt 28 minutes late.

The air conditioning was too weak. The train (1st class) was extremely overbooked. People walked through the aisle continuously to try to grab a seat from someone. The noise level as defeaning (even with noise cancelling Bose) and the service was well... not in service. Food that was advertised couldn't be ordered. The internet connection via WiFI wasn't working either.

Hopeless. Next time I visit the country I'll rent a car again.

It is a pop culture thing, I really wonder when such misconceptions will end. German are striking as often and sometimes more than the French, and their train are very often late, meaning a high chance of missing your connection. When I can I take a train without connection. Even in my very limited use of German trains, I still average around 50% missing connections.

I had to take 3 trains a few weeks ago, the first one was 20min late, meaning I missed my first connection. It turned out no big deal because the train I was supposed to get into didn't leave: it was broken! I had to wait an hour at the station, then I had the chance to jump into a packed train (remember the previous train which did not come?). It was such a pleasure.

It's a thing from the past. Last year the punctuality of Deutsche Bahn long range trains dropped to 65%.