Not saying I necessarily disagree with you, but just to give an example, the US has considerably better labor practices and labor laws than China. It's not perfect but there are protections about making sure people are paid what they're owed, how much you are allowed to work someone, safety protocols, etc. All of those things could, in theory, cost more money and make labor more expensive.
Compare this to nations that don't have the same work protections, where they can pay people peanuts and have them work much longer shifts with effectively no protection (e.g. Foxconn in China [1]).
This might translate to decreased cost, and Americans have made it excruciatingly clear that we're apparently fine with slave labor as long as it doesn't happen within the US.
[1] https://www.dissentmagazine.org/article/chinese-workers-foxc...