The number of Chinese students staying in the US after graduation has been relatively steady for the last 10 years; the number of Chinese students coming to the US, in contrast, has exploded, pushing the stay percentage down.
Instead of spending time on the product, or building a team, you have to waste time with idiotic immigration laws that were not written keeping the current tech jobs in mind.
So, even if you see an Indian or a Chinese grad stay back in the US, there's very little chance that they end up being entrepreneurs funded by VCs (unless they are from the top 10 universities in the US and started on their venture well before graduating). Not sure about China, but there are quite a few examples of Indian nationals fed up with US immigration laws, going back to India and startup a VC backed tech product company, valued over $100 million.
From what I have been seeing, the number of both Indian/Chinese students coming to the US for studying has gone down post the Trump administration. Also, I am seeing more Indian/Chinese folks going back home due to increase in engineering wages/opportunities. Of course, it's still not comparable to US but plenty-enough to live a very good life-style back home.
China has really great wages for programming (I should know), but lacks in many quality of life factors. For example, many Chinese won’t go back once they have kids because of educatio, hukou, and pollution factors. They would have to pay a lot to get around those.