If anyone is thinking of flying in China, go to Japan instead. QOL in Japan is a whole lot better. Japan is a wonderful place to live and work. China is not.
If anyone pays income taxes in China, just write that amount into your USA 1040 and deduct that from the amount you have to pay in US income taxes. The US IRS does not require any paperwork to prove this amount. Chinese companies will provide a "W2" form if asked. But you have to ask, they will not provide it without being asked.
Let's look at one example of China vs. Japan. China has blocked over 10,00 foreign websites from being accessed inside China.
https://en.wikipedia.org/wiki/Websit...mainland_China
In the not too distant future, China will have completely walled itself off from the Internet outside of China, except for a few "approved" websites. Nothing like this exists in Japan.