All technology rests in eliminating human effort. We have now hit the tipping point where entire industries will be replaced with new technologies. Drones building walls is just the tip of an iceberg larger than our entire planet. 3D printing is about to take over manufacturing as well as the construction industry. Your next car may be entirely built by a 3D printer with bots used to assemble parts made by the printers. Considering that a Colt 1911A was recently printed in appropriate metals and is fully functional printing a car engine should be a breeze.
I am aware that the unwashed will scream out to stop these job ending tools. But in fact our entire social and legal system faces a total rewrite. Imagine one guy in your neighborhood printing bicycles and handing them out for free or for only the cost of the powders used in the printing. The first totally printed bicycle has already been demonstrated. Everything from a pair of shoes to a fishing reel could flow from these machines. Even ideas such as import and export could be severely crushed by these new techs. This is already rapidly occurring.