Part of the foreign STEM graduate degree phenomenon — not all of it — is that foreign students bring in more money to universities. This is one reason why universities were worried about the sky falling during the pandemic, because they wouldn't be able to fill their seats due to the foreign student flow being cutoff, and even if they did refill the seats with domestic students, it wouldn't be at the same net 'profit" level in many cases, as they usually end up paying more in net tuition per credit.

https://www.npr.org/2021/08/09/1025193562/the-u-s-attracts-f...