>>18066828
Britain and Japan are spatially much smaller than China.
The US is close, but its growth coincided with the spread of rail and the telegraph, which ameliorated that problem. In many cases, the infrastructure actually predated the people that followed it. Also, historically the US had an issue of underpopulation instead of overpopulation. After the Indians died off/were killed off, the US had lots of land with good rail connections, but no one living there. Very different from China. While the US certainly had slums and the like, people had a lot more social mobility even in that era than you'd see in slums in 70s China or today in Jakarta. Because the US had so many excess resources for people to take advantage of.
China corralled its population growth which gave the State some breathing room when dealing with all those people that suddenly spawned in.
More is more, except when it becomes too much. A nation can only build so many railroads or cars for those railroads, or buildings for housing in new cities, or set up factories or industrial parks for private capital, etc. And there are diminishing returns on that pretty quickly.
Another 10 million people from the mountain farm country isn't going to help you build another city when those people pay a pittance in taxes.
China's ethnic homogeneity is overstated by the Government and 'arr rook same' /pol/posters.
Han Chinese is as vague as "Germanic European", and then you cluster Anglos, Swedes, and Austrians together and act like they're all the same.
Many dialects of Mandarin Chinese are basically unintelligible. And that has only started to change in the last few decades among kids. And that is beyond the millions of speakers of non-Mandarin Chinese. Including in places that were super important like Shanghai.
This 'homogeneity' never stopped the Chinese State from having massive issues governing its population before.
