I don't understand the weight assigned to factory closures. If I could make all the product in one robot-factory vs 3 people-factories, I would expect 2 factory closures. I think it must be coupled with the assertion that productivity isn't rising. But I think it is very interesting to look at the graph you linked compared to the graph for non-supervisory employees:

https://fred.stlouisfed.org/series/CES3000000006