Swiss railway is seen as the ideal DB should strive for, but fact is that Switzerland invests more than double per capita into its rail infrastructure. German stinginess now compounded over decades, and that's not the fault of management.
Would you mind sharing some examples? My only complaints with DB are cancellations and delays. Well, the ticketing might be a bit confusing the first time you realize "ticket" and "seat reservation" are two completely independent entities. Similarly, rules for which train you're allowed to take might be a bit confusing. But I wouldn't call it scamming.
Blacklist everyone who was involved above a certain rank. Put together an entirely new structure. The only real way to get rid of this kind of rot is to make the consequences of dysfunction hit.
Unfortunately, the DB first got hit by Thatcherite neoliberalism in the early 90s that led to "unprofitable" things like switches, railyards or lesser-used routes to be torn down and the real estate sold off (to prepare for a privatization that THANK GOD never happened), and then we got 16 years of Conservative traffic/infrastructure ministers whose job priority was to funnel money to Bavarian highways [1], not towards railways.
Unfortunately, while the left wing loves to prune its ranks in purity tests (partially because its voters demand accountability), the Conservatives have a solid "better dead than red" voter base.
[1] https://www.merkur.de/politik/csu-parteitag-bayern-markus-so...