adequate employees in rural Georgia, either because the wages they wanted were too high, or they lacked motivation, or they lacked education, or the population was too low and/or nobody who was qualified for these jobs in the US was willing to resettle to this place.
It's actually the biggest element of the story, since Trump's entire economic plan is premised on some mythical revival of the manufacturing sector in places like rural Georgie, and this Hyundai mega-manufacturing zone is presumably one of the biggest successes of the idea (though it is primarily a Georgia initiative that precedes Trump). They will be "incentivized" to hire American workers by force!
It's curiously a point of absolute cohesion in the otherwise incoherent and contradictory MAGA ideology: we will force the revival of manufacturing through tariffs, and then enforce that American workers are hired through immigration action!* Imagine believing that you're a free-market absolutist and these two interlocking policies are the centerpiece of your policy portfolio.
* Notice that this second part doesn't solve the problems of compensation, education, motivation, population, or relocation.