The DB is like Sparkasse and others not „the” DB but a bunch of different regional companies. Some of them around bigger cities decided to make a regional zone network like The MVV. At The same time many make other regional Tickets with others, like the bayernwald ticket, which covers part of these MVV network and non MVV networks.

So you might just think „well why not just make everything into a zone tarif”, but if you do that, if someone wants to go from Hessen to munich, since the zones are so big/many, they will have to pay way too much for many stations they will not even want to go to.

But for smaller places like the mvv network, if you abolish those zones, most stations will just just as much and the small ones which only accounted for cents if your zone ticket will die out.

So personally I think the problem with these tarif prices is just the over advertisement of time limited offers that only work for specific people and people not having properly learned about the 2 most important tickets in public transport: stripe cards for simple one way routes or zone tickets if you want a flatrate.