This is what is often famously referred to as the military-industrial complex.
The US military has a large pool of mechanics and technicians they constantly train who then go on to private sector. Building things, and building things right, take a level of physical dexterity and mechanical intelligence that must be honed.
Ever see a machinist run a hand over a milled surface, call it out of tolerance by 0.005” and then the calipers confirm? You can’t learn that from a book that shit is straight just 25 years of looking and touching surfaces that smooth. Drilling straight holes into metal frames that bend and give is an art.
You can’t let that die. So the military funds shops everywhere to build widgets for the war machine to keep people employed and those skills alive in the event that when we do need tens of thousands of them at once, there are seasoned veterans ready to lead the way. And in the mean time, they make $150k a year running a small machine shop in Michigan subcontracting for Northrup or Lockheed or something.