So your solution is to shut our eyes and let undocumented foreigners take the jobs that a well-educated American society could fulfill?
We know that fitting out and commissioning these kinds of factories takes foreign workers who have the subject matter expertise on how the parent company does it. But we have a history of not providing proper work visas for it and looking the other way.
On the other hand, if you don't let these people in, it's not clear how Hyundai gets a functional battery factory that's built like their other ones.
The old policy of looking the other way was broken. But suddenly "fixing it" with enforcement isn't too smart, either.
Most countries have a short term, productive work permit. We don't-- closest thing you can do is L-1 (and often this doesn't work: you can't hire workers for the purpose or use contractors).
Lottery based and slow systems like H-1B/H-2B don't work, and H-2B is intended for low skill labor. If we expect Korean and Taiwanese companies to establish factories, we must either provide a viable legal pathway for their technicians or accept the reality of ongoing B-1 visa violations. (I prefer the former).
(Oddly enough, ESTA/B-1 allow receiving training but not giving it).
Does this mean there is an equivalent in South Korea where the US could send workers on this Visa to receive training on how to build their (Hyundai) factories?
But sometimes you have a shorter-term need for some setup talent (especially when language skills and understanding local engineering conventions is important). This is much more common during plant construction.
I don't think you're going to quickly train US workers on how to decipher Korean documentation.