The problems lie elsewhere. IMHO there are two major problems with public transport in Germany. One is underfunding, which causes a lack of reliability, and plenty of lines that are overused. The second is complexity. Each local transport association has its own ticketing system, and they really like to make them complicated. The 49 euro ticket is a step in the right direction here, as it is one ticket for most (unfortunately with a few exceptions...) local public transport.
It should have no issue at all to align German wide but they never did it.
The Munich MVG for example is doing an experiment were you can pay by an app from some us company were you just start and stop your journey with a button and the app gives you the best price.
They could have instead just created some German wide software company sponsored by all the local public transport agencies and just do it themselves.
It's ridiculousl that modern problems are often not technical problems:-(