It basically costs nothing and it's a huge advantage for a country to be the dominant sink for international talent migration. Most countries have net brain drain where their smartest people leave... to go to the US. That the US has the opposite problem is really a trivial issue to complain about, and anyone invested in its success should want the imbalance to continue.
And frankly if you're an American high-skilled worker who is concerned about foreign talent "replacing" you (an absurd idea in a labor market where demand continues to outpace supply, and will continue to do so as long as technology advances), then are you actually as highly skilled as you think you are? If you're being outcompeted by foreign talent then you need to "get good" - it's a skill issue.
The argument for foreign workers replacing domestic workers in unskilled jobs makes more sense, because the demand is for commoditized labor and there's negligible difference between employees beyond how little they're willing to be paid. But for high skilled work, by definition, it's your skills that should differentiate you. If they don't, then that's your problem to solve. It shouldn't be up to the rest of society to lower the floor of high-skilled work to accommodate your lack of skill.
For now, H1Bs don't replace truly highly skilled workers. What they do have an impact on is companies not investing in hiring junior employees and training them up. Thus, the disadvantaged people that can't attend college, who would customarily be trained by their employers, are left out in the cold when you can just import already trained people from overseas.
Your comment is very atypical in this thread. It is the only one that puts the impact of the visa in perspective. The displacement of risk from company to employee.
This is my main concern of H1B's impact, lack of training or opportunity for existing candidates. It is telling how a few other comments mention the skills gap but all of them focus on it being a employees problem and to solve it they just need more college or training. While I can't argue with the positive impacts of H1B's creating value there is a continuing cost imposed on society to make the individual take the risk of training instead of the company cultivating a workforce. I think individuals do need to have some skin in the game when they receive a investment from a company but by completely displacing the cost on to workers and making up for lack of investment by allowing more H1B's seems to be a shortsighted solution.
And frankly if you're an American high-skilled worker who is concerned about foreign talent "replacing" you (an absurd idea in a labor market where demand continues to outpace supply, and will continue to do so as long as technology advances), then are you actually as highly skilled as you think you are? If you're being outcompeted by foreign talent then you need to "get good" - it's a skill issue.
The argument for foreign workers replacing domestic workers in unskilled jobs makes more sense, because the demand is for commoditized labor and there's negligible difference between employees beyond how little they're willing to be paid. But for high skilled work, by definition, it's your skills that should differentiate you. If they don't, then that's your problem to solve. It shouldn't be up to the rest of society to lower the floor of high-skilled work to accommodate your lack of skill.