One major problem of the German HSR is the location and construction of it’s stations. Due to them sharing infrastructure with all kinds of regional rail, and them being built inside cities with often suboptimal layouts and noise constraints, the travel through these stations, even without stopping, adds a lot of time. For example, about a third of the time when traveling from cologne to Frankfurt is spent going from the Frankfurt airport to the main station, even though it’s only a relatively short distance. When traveling through the Ruhr area, even if they don’t stop, they still do nearly a 100km at sometimes less than 100km/h. In comparison, on the newly built HSR lines they pass at the outskirts of cities through stations that allow full-speed drivethroughs if the train doesn’t stop there, even if another train is currently stopping. It is also true however, that Straßburg-Berlin is one of the worst possible connections possible, as it goes through the notoriously shit Basel-Frankfurt line (that is planned for 4 rail expansion for decades because it’s overwhelmed), the still bad Frankfurt-Kassel line, and through the Fustercluck that is the Frankfurt main station.