I guess Hong Kong is not included as the IMF list (see quiz methodology) includes countries. If Hong Kong is counted as China, this would be the reason it does not make the list.
Also, despite having the world's second highest *total* GDP, on a per-person basis China is still about on-par with Russia. When adjusted for Purchasing Power Parity (PPP), which controls for differences in what can actually be purchased per dollar of GDP in the country, they rank slightly higher than Mexico.
China isn't nearly as impoverished as they used to be and spent decades growing rapidly, but outside the cities a certain level of poverty still persists.
Atlanta is home to 7.3 million people and is in a developed country (The United States) and yet Detroit is included despite being home to 5.1 million people. also what about Nagoya and Berlin?
Also, despite having the world's second highest *total* GDP, on a per-person basis China is still about on-par with Russia. When adjusted for Purchasing Power Parity (PPP), which controls for differences in what can actually be purchased per dollar of GDP in the country, they rank slightly higher than Mexico.
China isn't nearly as impoverished as they used to be and spent decades growing rapidly, but outside the cities a certain level of poverty still persists.