If hiring foreigners is only about getting cheaper labor, why do all the best paying tech employers (FAANGs, unicorns, quant trading firms etc.) have so many foreign born workers on staff? America is only 5% of the world’s population, if you want to hire the most talented people possible, you will inevitably see substantial foreign representation. I work with plenty of non-citizens who get paid millions of dollars a year. I don’t think they were hired because they were cheap.