That works both ways. China has a so called 1000 talents plan. Effectively a lottery for USD ~$3m for a person with a PhD level education and a passable business plan.
I personally knew one exceptional foreign chemist who, after living in China for 15 years, finally dared to do "deal with the devil" and managed to land a defence contract. She was just 27 when she started her business as a continuation of her PhD.
> The Thousand Talents program primarily targets Chinese citizens who were educated in elite programs overseas and who have been successful as entrepreneurs, professionals, and researchers
I mean if anything this feels like confirmation of my original point. You only need to invest significant time and treasure into luring people back if they're leaving.