Living in NZ, the graphic from the 2020 election is misrepresentative of normal distribution. The current Labour govt roared to an unprecedented sole majority victory off the back of successful Covid elimination (at that point anyway). Recommend using data from the 2017 election that shows a more traditional spread. We use a mixed member proportional system. The Green Party who sits further left than labour won the CBD seat in our largest city. Literally the most left leaning party won the densest possible seat. The only electorate seat they won.
The graphic shows that National (Blue/right) won central, dense Auckland Suburbs, along with the less dense Waikato rural region. It shows Labour (Red/left) won everything else, rural or urban regardless. But 2017 shows the urban/rural split better