“The population of China right now is 1,443,145,867 so if they lose 500 million, they will still have nearly 950 million people.”
950 million people standing around in a radioactive rubble, with zero food, infrastructure, dams breaching even if they aren’t hit, no military, or even the ability to make it to the next town without walking. So that’s not the same as 950 million people in a functioning nation.