The problem is the concentration of money and talent (the US trajectory is basically just software and finance now) leads to an inability to react to changing conditions and a deep dependence on foreign nations.
If China did something wild and pulled the plug on all US exports, the great minds filled with years of software and finance would be pretty much useless for stabilizing the situation. You want a diversity of smart people in many industries.
They are right now sure, but the scenario as quoted in the previous post could just as easily have risen from China's side as a response to some geopolitical drama and the US would have been just as unprepared for it as it was for the current self foot shooting. A strong manufacturing base is a national security asset and the US has mostly allowed it to rot out. Some niches have been propped up by defense spending like weapons design and manufacturing or military shipbuilding, but even those are downstream industries that need a general base to stand on that they no longer have and it shows.