The problem is the infrastructure. There is already the Generalsanierung under way, it will take a decade and secure the status quo.

A lot of delays are due to rail corridors being at capacity, but overboarding bureaucracy makes any improvement there a generational project.

Hamburg - Hanover has been discussed for decades with strong opposition from NIMBY groups with no solution in sight.

But even if there is no opposition things take ages. E.g. for restoring the 2nd track and electrification between Cottbus and Görlitz the plan is now to finish the project by 2041.

This is absolutely insane for 100km of track that were removed as WW2 reparations.

And looking at previous projects it's unlikely to finish in time.

The new S-Bahn track in Berlin between the main station and Gesundbrunnen was supposed to open in 2017. It got delayed over and over and is now finally scheduled to open by the end of this month - just a delay of 9 years.

And that's with an interim station because the real station at Hauptbahnhof wasn't finished in time - and no intermediate stop, that's now also in the planning phase and will mean the line will have to be interrupted again in the near future

When Generalsanierung is over, they can start again right away. That's just the maintenance/running cost. What is needed is building turnout tracks and other stuff to avoid delays. The delays turn people away from riding trains, or buying tickets. We want to combat climate change, but our train service is so bad, that people prefer to drive 4-person cars, alone, for hours, during which they need to be paying attention to the road at all times, instead of sitting in a train and relaxing, or getting stuff done, that they can do during the ride. There is something fundamentally wrong.