Wow, 10,000 per km² sounds crazy ambitious. By those standards, Germany is a ghost land, cities here barely reach those numbers in the densely populated parts, certainly not on average.
Or maybe we need an article about ghost countries.
Yeah, but to get those levels, they fill blocks with dozens of identical 25 story apartment buildings. E.g.: https://pulitzercenter.org/sites/default/files/styles/node_i...
You could find an example of a row of identical buildings in any country, it doesn't prove anything.