First, anecdotally, I've known a number of Chinese-national but US educated persons, who after receiving their higher education and 5-10 years of work, returned to China. The main reason being the "bamboo ceiling". Often, returning means accepting a lower salary but with higher career trajectory and a more peaceful life. I don't think throwing visas + cash at researchers (at least those I've worked with) would alleviate all the cultural problems that lead them to return home in the first place.
Secondly, a recent push for change in Visa distribution (S.386)[1]. Would make it extremely difficult to attract talent. As this bill stands it will significantly harm prospects of Chinese applications for EB2 visas. The kind of change being suggested here (recruiting researchers and engineers) falls into the EB1 - EB2 category. Given how difficult it's been to even get a bill changing pool statistics this far, I doubt you'd be able to do anything of the nature you're mentioning.
[1]: https://www.congress.gov/bill/116th-congress/senate-bill/386
However, I don't know if China would be more successful in convincing it's top talent to stay with their families, and I have no idea how to sell this idea politically to American voters. The stereotype of Chinese culture is that they tend to be more collectivist, and the stereotype of the general population of American voters would most likely rather spend any money on Americans first. For the later problem, it is hard to articulate concisely the roundabout way this ends up causing brain drain, and the eventual benefits to the US citizenry. It is much easier to sell "China did something bad, we will punish them with tariffs" than "Chinese government bad, we will pay top Chinese citizens to defect."
You can't turn the clock back. The anti-Chinese sentiment is very high now in America.
There must be many wealthy, educated HKers who are interested in leaving at this point and they would be a huge asset to whichever country accepts them.