Automation, since its inception, has drastically increase the production of labor and contributed to the disappearance of many types of human labor.
In Wealth of Nations Adam Smith divides the price of a commodity into three parts: profit from stock, providence for labour, rent. Automation today is more like labor than stock.
The earliest account I know to call automation slaves is in the US, where the introduction of factory machines are described by “mechanical slaves” by the news paper. (A quick search turned up this video that describes cars and planes “mechanical slaves” too.)
Note: I do not humanize mechanical and electrical machines.
Automation also give rise to Marx-flavored communism. In Das Kapital, Karl Marx critized the factory as a system of exploitation.
Today, the knowledge of how to create automated systems, physical or otherwise, is still mastered by the few. Even though the Internet contains the entire text of how to do so, few people know how to access it.