Yeah, the dependency graph for scheduling trouble to procreate is massive. Not comparable at all to a star topology as in France, or to a two coasts topology as in Japan. Closest thing might be Switzerland, but while that network is also very dense, it's also so small it might just as well be compared to some of the larger subway networks.
And then there's a pet hypothesis of mine, that a factor in the unreliability of German rail is the famous absence of a general speed limit on the Autobahn: that this might make DB strive for fast best case connection times more than it would if driving was slower, pushing them to schedule an unrealistic house of cards with not enough slack to recover from the unexpected.
Yeah, both Switzerland and the Netherlands have distributed networks like Germany, but their relatively small size means that they don't need to design around speed, and can focus more on synchrony.
That said, this doesn't mean it's impossible the fix Germany's trains. Germany's network did work quite well before, and it can again. The fixes are happening right now, but it's going to get worse before it gets better, because all the construction that needs to be done interferes with the network.
And then there's a pet hypothesis of mine, that a factor in the unreliability of German rail is the famous absence of a general speed limit on the Autobahn: that this might make DB strive for fast best case connection times more than it would if driving was slower, pushing them to schedule an unrealistic house of cards with not enough slack to recover from the unexpected.