I think you're missing the point OP was making. He's saying it's profitable but not optimal, those who recognised that quickly outstripped the slave owners in wealth.
I could ask you about your spending habits and why you don't pump all your money into an S&P 500 ETF, but that's ignoring time and consumption preferences you have, as well as perceived opportunity cost. It's not a useful observation to make at an individual level.
I could ask you about your spending habits and why you don't pump all your money into an S&P 500 ETF, but that's ignoring time and consumption preferences you have, as well as perceived opportunity cost. It's not a useful observation to make at an individual level.