Just because it was true in the 19th and 20th century that human resources can reallocate from agriculture to manufacturing does not mean it will continue to be

Just because it was true in the 19th and 20th century that human resources can reallocate from agriculture to manufacturing does not mean it will continue to be true in a future context. Every day our R&D is chipping away at the necessity for a human labor force until we get to the day we have 0 percent employment.