FYI what you described is hot-potato routing: each AS gets rid of it as soon as possible.
You may think this is unfair, and yes, it is, but it's also quite logical when you consider you don't know where the packet is going in the destination AS. If you have a network spanning Berlin and Hamburg and the packet is going to a different network that also spans Berlin and Hamburg, and you interconnect at both points, and you don't know which city it's actually going to, handing it off at the closest interconnect doesn't risk round-tripping it for no good reason.
I'm interested in your definition of fairness that makes hot potato routing unfair.
In my mind, hot potato is fair, every packet gets treated the same, and (mostly) every provider does the same thing.
> it's also quite logical when you consider you don't know where the packet is going in the destination AS. If you have a network spanning Berlin and Hamburg and the packet is going to a different network that also spans Berlin and Hamburg, and you interconnect at both points, and you don't know which city it's actually going to, handing it off at the closest interconnect doesn't risk round-tripping it for no good reason.
There are ways to help with this, BGP MED (multi-exit discriminator) or path extention can help guide towards the best place to deliver traffic. But especially for last mile traffic, you do want it on the destination network sooner than later; if traffic is genetated in Berlin, and the ultimate destination is Hannover and the Hannover endpoint is connected to both Berlin and Hamburg on the destination network, delivering at Berlin provides a better experience than delivering to Hamburg, even though Hamburg is closer to Hannover, because the transit to Hamburg was unnecessary. And if the destination is only connected to Hamburg, delivering in Berlin works about the same as delivering in Hamburg (depending on capacity and use from Berlin to Hamburg on both networks).
There's certainly situations where having options would be nice, but having options makes things complex, so typical users can't really influence routing. If you have v4 and v6, you may find that routing differs between the two and that does give you a bit of a choice.
The unfairness of hot potato routing is that it aggressively tries to offload as much cost onto other companies as possible. It may be how business works but it's not really an ideal way to build a system.
You may think this is unfair, and yes, it is, but it's also quite logical when you consider you don't know where the packet is going in the destination AS. If you have a network spanning Berlin and Hamburg and the packet is going to a different network that also spans Berlin and Hamburg, and you interconnect at both points, and you don't know which city it's actually going to, handing it off at the closest interconnect doesn't risk round-tripping it for no good reason.