That's pretty easy to understand though: that 150 soul village is in the middle of a much less dense area than the heart of Berlin, so a line that would pretty much always be saturated in Berlin will have plenty of capacity left in that small village.
For the best - and cheapest - bandwidth: total deregulation of telcos. Like what happened in Romania, which has the cheapest and best connectivity of any European country. Which really isn't what you'd expect.
the lines rarely are the issue but the copper-cable length from home to the DSLAM:
Less cable-meters mean less reachable households per DSLAM. And the DSLAM costs - both hardware and maintenance. Regardless if 2 or 20 customers connect. So the carrier wants to conect as many as possible and so they have to suffer cable length.
For the best - and cheapest - bandwidth: total deregulation of telcos. Like what happened in Romania, which has the cheapest and best connectivity of any European country. Which really isn't what you'd expect.