Generally churn factors. Stuff like importing young talent opening up further exposure to that talent moving on but also atrophying your in-country educational structures and investment. Kinda the societal version of "publish or perish" - always chasing just short-term dollars, without regard to long-term planning. If you want to import people to do the good jobs, but also want to ship the cheap jobs away, what happens to everyone squeezed out?

We can retrain and redistribute resources to them, but for some reason the people who are most concerned about short term profits are the least willing to share them with others.

You might like to ruminate on teh fact that while Trump demonizes immigrants out of one side of his mouth, the resort he owns at Mar-A-Lago- was able to get 70 H1-B visas to hire hotel staff, despite the availability of some 5000 such people in Florida's state employment opportunities database and a whole lot of US citizens in Puerto Rico that are in search of economic opportunity right about now. Not that you were making a partisan point, but this is a great example of how the rhetorical divisions in American politics do not line up with the business practices.

Right, it's a partisan point but it shouldn't be. I know perfectly well Trump is often full of shit and do-what-I-say-not-what-I-do. But unpartisanifying the discussion of pros/cons of immigration vs outsourcing vs insourcing vs how to help other countries vs what to focus on in our own borders would be beneficial.

It might, but I can't help feeling you're assuming your conclusion a bit by treating migration as the problem. Maybe it's something else in the nature of the economic system. Other species seem to get OK without our hyper-territoriality.