Doesn't the timeline coincide with women entering the workforce (increasingly after WW2) and massive immigration to the US (after the Immigration and Nationalit

Doesn't the timeline coincide with women entering the workforce (increasingly after WW2) and massive immigration to the US (after the Immigration and Nationality Act of 1965)? Basically, a large influx of (at least potential) workers increased the supply and lowered the price (in wages and benefits employees could demand) of labour. There are other effects, like specialization, which make consultants much more effective at certain tasks with which regular employees don't have a chance to build experience. However, like lowered transaction costs, I don't think this is crucial.