And here I thought Americans were the only ones with a chaotic set of transit agencies serving the same region
In all seriousness though, I'm very curious about the structural incentives at each of these places. Presumably, the people who run them care to some degree about customer experience. How then have they built a system that clearly doesn't?
the ticketing system is completely decentralised and the alliances did for to improve customer service and ease of use. Without them you would have to buy a different tickets for tramway, underground and regional trains, since they are probably completely different operators.
EDIT: it's really complicated. One ticket for all is not that easy because there are massive pricing differences depending on the needed infrastructure and subsidies.
Fun fact: sometimes there are even different operators for the same mode of transport.
Cologne and Bonn have overlapping tram/metro grids, so some of the lines are serviced by both transport agencies (KVB and SWB).
Likewise the regional trains are sometimes operated by someone other than DB, like the Eurobahn. Because these organisations are part of the same infrastructure and the tickets are valid for both, they are treated like regular DB trains in station plans and connection finders.
I once tried to find out whether a ticket for regional trains (i.e. S, RB and RE lines) is valid for the Eurobahn trains (which are denoted as "ERB" in connection finders). Apparently DB service employees don't have to know these things. In the end I found out that they're indeed valid even if they're not listed explicitly -- but I literally had to wait for a conductor to check my ticket (which would have resulted in a fine if it hadn't been valid).
In all seriousness though, I'm very curious about the structural incentives at each of these places. Presumably, the people who run them care to some degree about customer experience. How then have they built a system that clearly doesn't?