I don't think the problem is that 3rd worlders are willing to accept lower standards of living - over time that problem fixes itself.

I think the fundamental problem is that USA is highly regulated to the point that even with workers who are 3-4x as productive it's just not worth it to produce here.

Another big problem is reserve currency status of the US dollar - if you can pay for your imports with a printing press rather than real goods and services, it's going to make sense to do a whole lot of that. It's also going to make sense to import as much as possible rather than produce even for your own consumption.