How do you prove this assertion? Could it not have also happened because Routine labor is also the cheapest to outsource? Couldn’t Nonroutine labor have become far more profitable to invest in?
Computers have enabled global interdependence, but I would argue not by “shouldering” labor, an interestingly physical choice of words. Instead, by easing the flow of capital from wealthy countries into less wealthy ones, and creating a global production workforce that can do better work for cheaper.
Trying to do global macro-economic analysis of the impact of technology by looking only at the growth (or lack thereof) of American jobs is myopic. America is not a closed system, and it’s labor pool can shrink for many more simplistic and capitalistic reasons than the advance of AI.