For perspective, Canada, a country 1/10th the size of the US, brings in 30,000 refugees each year. The US brings in 18,000. This means Canada brings in 25X the number of refugees per capita than the US does.
Canada, a country 1/10th the size of the US, brings in 300,000 new immigrants each year. The US brings in 1M. This means Canada brings in ~5X the number of new immigrants per capita than the US does. [2]
[edit] This rate has been consistent since 1992.
[edit] I originally stated the US brings in 140,000 immigrants per year, this was a mistake, my cursory search led me to the cap on employment based green cards, not total. Factoring in family members of US citizens, it's ~1M. By Immigrants I include green cards per year, as everyone else is by definition a non-immigrant. It is my understanding the Canadian number is the same category.
Blanket requiring additional pay for H-1Bs seems fine, but leaves startups in a difficult spot where they're unable to bring in the same level of foreign talent that bigger companies are, as, of course these rules do not take into account equity based compensation. As it stands, 4 out of 5 H-1B holders make more than average Americans.
The process of bringing in H-1Bs is already so expensive, arduous and wasteful that companies aren't going to be bringing in huge quantities of "US replacement" labor. I certainly wouldn't if I were in charge of hiring.
[1] https://qz.com/904933/a-history-of-american-anti-immigrant-b...
[2] https://www.boundless.com/immigration-resources/how-to-read-...