500 years ago there existed an entire industry based upon copying books by hand. Typically the process was done by monks, sitting in monasteries, often worshipped as semi-gods may I add. 50 years later the industry was replaced by the printing press in its entirety, and none of these guys could hold their jobs.
A slightly more recent example can be found by looking at the process of manufacturing cars. When Henry Ford created his first car, it took 18 months to assemble a car, and the process typically included dozens of humans, working non-stop on the same car for 18 months. 20 years after Ford created his first factory, he was rolling out a car in 3 weeks.