Also, it's only cheap because huge companies are losing billions subsidizing it. The reason factories aren't entirely automated is because few companies can justify spending a billion dollars to fully automate their assembly line. I work at a factory where one machine outputs product single file and the next machine requires the product come in double file. The company pays a worker to stand on the line and split the output from the one machine into two lines.

I figured that would be super easy to automate but one of the engineers explained the company only gives money to do something if they can prove the money will generate a huge return, and automating that part simply doesn't generate a big enough return to justify the cost. If a machine breaks down 1 hour a day they'll fix that before replacing a worker. A machine can generate $100,000 an hour, so it being down an hour each day is a loss of $100,000 per day. Replacing a worker saves the company $250 a day. Replacing the worker that splits 1 line into 2 lines isnt a priority. Keeping machines at 100% uptime is what the focus is.