They created the Thousand Talents program for promising and distinguished researchers, Chinese or otherwise, to work and stay in the country with salary comparable to the West, in nominal terms, and many extra privileges. [1]
Pollution is a major concern among those who are interested and this gives additional urgency to the government.
Basically, they understand very well that top talents are essential for developing advanced technologies they need, and they are pushing very hard to develop native talents and attract promising ones from other countries. This is the Singapore playbook that has propelled their two universities into major institutions in engineering and other fields within a few decades. (Engineering programs in both Singaporean universities are now ranked in the top 10 or 20 in the world. Also, both Tsinghua and Beijing are ranked in the world's top 10 in AI publications recently, but they plan for more universities to move up in more fields.)
[1] https://en.m.wikipedia.org/wiki/Thousand_Talents_Program_(Ch...