Well, they likely need to pay income tax and social insurance in their own country. The burden has just been shifted to them.

To be fair, I’m not 100% sure how this works in the US, in PL where I’m from and probably in all of the EU countries if you are on a job contract then the employer pays the taxes and social insurance for you. If you are self-employed / freelance you have a business registered in your name and it’s your responsibility.

Either way, I don’t see how the taxman’s cut disappears. Also lot of countries have higher taxes + social insurance than the US.

If you really want to make a case, you can say that the contractors from a low-cost-of-living countries may undercut American workers (but then, if they work remotely I think they mostly undercut the office jobs, not “workers”) because they ask less money for the same.