That's a matter of train infrastructure and frequency keeping up with demand. There's a big lag there. You don't just buy 100 new trains overnight. It's a symptom of ramping up. Not of high usage.

I live in Barcelona and here the metro comes every 2-3 minutes. Even during the night it might be 7 minutes. This helps so much with congestion but also trip planning: no need to check train times before you go. Id imagine busy routes in Germany could do similar.

The big benefit of this is also not needing a car. Not having to worry about maintenance, write-off, finding parking and the cost thereof, summer and winter tyres, damage, no-claim bonus, travelling while having drunk, going back from a different place than you arrived. It's so incredibly more convenient than having a car. All at a flat rate of 21€ here.I hope never having to need one again.