The problem is, urban areas have grown so massive that they can just screw over rural areas by sheer numbers - in Germany, 77% of voters live in urban or agglomeration areas, that's way blowing past the usual 2/3rds-majority requirements.

At that point, who is to prevent parties from solely catering to urban area voters at the complete expense of rural voters? It's already seen as problematic that most public investments like infrastructure get directed towards urban areas, the term "flyover states" exists for a reason and we've been seeing for the last decade just how damaging that can be for a democracy.

[1] https://www.deutschland.de/de/topic/leben/stadt-und-land-fak...