I'm not familiar with China's system. But let's not pretend a lottery based system, where the only thing that decides whether you can stay in the country or not, is random number generation, like H1-B is great.

China's system is basically just "No, you can't stay". As of 2010 exactly 1,448 living immigrants had managed to become citizens. In contrast, the US naturalizes 700,000 every year.

The country actually has more billionaires than non-Vietnamese refugees.

Right. China is in the business of colonising other countries - not being colonised itself.