The problem that the US has supporting mass manufacturing and assembly is that companies like Apple stopped making things there, and once that happened all the expertise and supply chains to support that manufacturing was lost, meaning that now it's not possible to make stuff in the US anymore and those companies are totally dependent on China which didn't make this mistake. Part of the problem Apple had was that they couldn't get items as basic as screws in the quantities needed from US suppliers, and why would they be able to when there's no US manufacturers which need those items in those quantities?