Britta Glennon in 2020 (updated Sept 2024) wrote a paper which succinctly states the demand for foreign talent from Silicon Valley, and how Silicon Valley eventually has its way. From the abstract:

“Highly-skilled workers are not only a crucial and relatively scarce inputs into firms’ productive and innovative processes, but are also a critical resource determining competitive advantage….Firms respond to restrictions on H-1B immigration by increasing foreign affiliate employment at the intensive and extensive margins, particularly in China, India, and Canada….The most globalized multi-national corporations are the most likely to respond to [skilled worker immigration] restrictions by offshoring….these firms hire 0.9 employees abroad for every visa rejection. More broadly, the paper provides evidence of a push factor for internationalizing knowledge activity.”

I have posted on the extreme dependence of American firms on foreign-born AI talent: The United States has a large lead over all other countries in top-tier AI research, with nearly 60% of top-tier researchers working for American universities and companies. The US lead is built on attracting international talent, with more than two-thirds of the top-tier AI researchers working in the United States having received undergraduate degrees in other countries.