The visas certainly contribute to the problem, but I think these factors are more important:
1. We have been encouraging far too many kids to go to college relative to the demand for college graduates.
2. The graduates are generally less productive than those of prior generations, due to grade inflation, declining work ethic, racial/sexual quotas, and bad majors.
All that happened when the US feral government started handing out student loans like candy to dumb 18-year olds who had no concept of cost-benefit analysis.
The colleges could charge anything they wanted, and the dumb 18-year olds would borrow it.
That’s how the colleges got all that money for affirmative-action “perfessers” of imaginary degrees.
An unpopular view here, but it must be stated. There was a time when the American worker was unquestionably worth a premium salary. Now that jobs have to be designed for the lowest common denominator thanks to the corrosive effects of television culture and government education on our workforce over the last four decades, companies figure they might as well cut costs using the H1B program and other tactics.
Sure, there is a lot of short-sightedness in corporate hiring, but talent acquisition and retention has become a monumental challenge for American firms...just as the Socialists intended.
I’d still look at just dropping the 1965 Immigration Act and its associated programs.
Then prioritize citizens in any subsequent replacement.
So the visas are allowing the government to keep the tax base in country.