No they didn't learn about the iteration. Actually they learned, that the populism cannot be sustained (the plan should be named 90 euro ticket 1 euro/day, but for populism they "removed one zero"), again, they borrowed our money to be able to follow a populist agenda, but the Federal government said already that they won't be able to keep up with that: with a ridiculous excuse: "It is not a federal issue, but the federal states are responsible for that" https://www.tagesschau.de/inland/nachfolgemodell-neun-euro-t...
The results until now: 3/4 of the people still driving their cars: https://www.focus.de/auto/news/ergebnis-ueberrascht-umfrage-....
So 2.5 billion euros (actually much more, see https://www.stern.de/panorama/-9-euro-ticket-macht-krank----...) is the most expensive "almost free" train ticket in the world...
A (conservative) 25% reduction in car usage for a neglegible fraction of the GDP sounds like a great deal, actually.
Point is, it reduced automobile use by a significant amount because people do prefer to use the train when the price is right.
Which means that with appropriate subsidies you can seriously improve the existing transport infrastructure. 10B a year is a pittance compared to the good it would do - Especially with the looming energy crunch.