Why do you keep living in delusion?
Despite the fact that your country did so many mistakes in recent years due to which China is bearing the consequences, you still don't learn.
Firstly, most of these 140 million mentioned are tourists, who won't anyways be allowed to stay in their visiting countries.
Next, for the students and professionals, a high number of people choose to stay in the developed west in the higher bracket of talent.
That is people who are visiting the top universities in the US for STEM, and are the most skilled, continue to stay in the US.
The ratio of returnees has increased only because these days many people going to US from China are rich spoilt kids who don't even have the proper skills.