" In contrast, Micron and SK Hynix each have well over 30,000 employees and Samsung’s memory division is estimated to have over 40,000. "
That's fools logic. They can scale up quite easily, this isn't a cottage industry here with individual weavers turning out individual carpets. More people is worse not better, it leads to inertia. The machines they need, can be second sourced in Germany and UK (and some in China), so the factory kit is replaceable. The software design tools they already have. None of that is irreplaceable.
As to whether they can do it in 4 1/2 years? That seems a trivial goal. They could do that in 1 year if you pushed them.
Look at the result of the tariffs. How many Chinese made items have had their manufacturing moved to the USA? ~none. Close to zero. You still cannot make the products in the USA, because they could not be exported at a competitive price to markets where US tariffs don't exist to skew the market in USA favor. I doubt they even have the technology needed at this point to make stuff, even if it was only for US markets.
It's not going to change either, USA trades at a loss and has since the 90s. It's propped up by money printing. Each dollar made is leveraged up, and given to the Mnuchins/DeVos's/Carlson's/Swanson's/Beal's. That inflates the GDP number. It's why housing is overpriced, stocks and other assets are overpriced, its simply billionaires are awash with free money and have nowhere productive to put it. So they pump up asset values for the rest of Americans.
The whole economy is locked into that. To borrow money to fund that increasing deficit, that GDP number needs to keep increasing, to keep increasing as the real economy underneath shrinks, they have to print more and more money. Productive workers cannot work for low wages, if their houses costs so much, and their pension plan is built on overpriced stocks, and their health insurance costs an insane amount. So wages can never be competitive.
Contrast that with the export tariffs. Soy, Maize, Wheat, Chinese markets poof gone. Farm exports easily replaced. Huawei simply re-sourced US chips and replaced Google store with their own.
Trump's Atlantic city projects. $700 million in junk bonds supported by $820 a day in profits. That's what it reminds me of. All bluster, smoke and mirrors.