US immigration is broken beyond repair. Hard to summarize all the issues in an HN comment, but you may find some of Cato's work on this relevant (e.g., https://www.cato.org/policy-analysis/why-legal-immigration-n...).

Briefly, US immigration has little to no concept of merit. The simple (in theory but hard legislatively) fixes are to make it a lot more like a points based system that favours a combination of skill/education/wages instead of race or country of origin and on the worker rights front removes all dependence on the employer for immigration.