As far as DB goes, I'm pretty sure it's mostly an issue of systemic technical and consequently social collapse.
The system runs beyond its limits and consequently the culture collapses because the people inside learn they have no agency.
The German rail network is quite good on paper, with dense and high frequency connections even to relatively remote locations.
But keeping that functional (particularly with constantly rising demand) requires far more investment than it receives.
All the examples of great rail systems (France, Switzerland, Japan) are both simpler in network structure and invest more relative to their passenger load.
The system runs beyond its limits and consequently the culture collapses because the people inside learn they have no agency.
The German rail network is quite good on paper, with dense and high frequency connections even to relatively remote locations.
But keeping that functional (particularly with constantly rising demand) requires far more investment than it receives.
All the examples of great rail systems (France, Switzerland, Japan) are both simpler in network structure and invest more relative to their passenger load.