It's more complicated than this, The US has multiple challenge in its own domestic talent pipeline. In a world of finite slots for elite production and elite employment the US must own the outcome of allocating those slots internationally and the resulting under-employment of its domestic population.
Whether these slots should be finite or not is an independent problem, however for various reasons the slots are currently finite and potentially reducing in volume with income inequality.
> US must own the outcome of allocating those slots internationally and the resulting under-employment of its domestic population
Slots are being cut across the board. For international students as well as domestic ones. Also, we’re talking about a couple hundred seats. And again, of graduate students.
> Whether these slots should be finite or not
They’re grad students. Extremely skilled. Artisanly trained, pretty much. There are fundamental limits on how many we can productively have. I’m guessing none at MIT are wasted.