That's just it: American tech companies aren't staffed by Americans anymore. Liang Wenfang, the founder of DeepSeek, made the point that he values developing domestic Chinese talent over importing foreign experts. It seems to have worked.
The lack of a PhD probably has more to do with the structure of Chinese education but these people were basically studying like PHDs.
https://www.firstpost.com/explainers/china-deepseek-ai-full-...
China has a reputation for being a "paper mill" place though, so not sure that publishing papers has any value whatsoever as a quality indicator.
Only those tech talents in the USA who are useful for some big tech agenda are not languishing.
https://www.bloomberg.com/graphics/2023-black-lives-matter-e...
Job growth amongst foreign born residents in the US has significantly outpaced native born job growth:
https://www.bls.gov/opub/ted/2023/foreign-born-workers-were-...