If your argument is that when immigration is restricted, capitalists will run out of options and will have to raise wages and improve conditions, I'd say that is simply wrong, for which there are several reasons.

First, they can off-shore, like they have been doing for decades. Second, if labor becomes tight, companies accelerate automation and workflow restructuring - which destroys jobs rather than improving conditions for remaining workers. Third, when labor is scarce, large firms typically consolidate, which lowers the competitive pressure to raise wages, since monopsonies and oligopolies neutralize the bargaining power gains of a tight labor market. And lastly, capital does not need to keep growing headcount: if labor is too expensive, firms simply grow more slowly, invest less and try to extract more from existing workers - which is the opposite of working condition improvements we all want.

Fundamentally, the reality is that capitalists will never run out of options, unless capitalism itself is abolished and wealth and property are confiscated. The reason for this is simple: under capitalism, capital is structurally mobile, whereas labor is structurally immobile. This creates a massive power asymmetry. Capital can always reconfigure itself to avoid rising labor costs. Restricting immigration does not force capital to yield. Only changing the rules of capital-labor power does. And you cannot do that by relying only on one lever (immigration). Not only is that the weakest lever, but also, you need a complete restructuring of society, including the way the economy is organized and how the government works across all levels.

I'm generally supportive of the populist sentiment, but the desired outcomes will only be possible with prolonged effort that will likely span decades. Gimmicks like $100k fees for H1-B visas will be massively counterproductive, as they ultimately harm, not help, the people whose interests need to be protected.