An economy is about the volume of cashflow (value flow), not magnitude of wealth. If you have all the money in the world, you will find there is nothing you can buy.
While a large number of, not free but very low cost, laborers will build individual wealth for the small percentage of the population who use them, those same laborers do not participate in the economy. So you end up with very large supply and very little demand, little or no reason to innovate, and a stalled engine of growth.
Slavery, or even low wage workforce is bad even from the point of view of entirely selfish actors. It erodes the market eventually killing the entire economy.
The lesson is, if you want to get rich don't reduce the cost of your labor force, increase the value of your production.
While a large number of, not free but very low cost, laborers will build individual wealth for the small percentage of the population who use them, those same laborers do not participate in the economy. So you end up with very large supply and very little demand, little or no reason to innovate, and a stalled engine of growth.
Slavery, or even low wage workforce is bad even from the point of view of entirely selfish actors. It erodes the market eventually killing the entire economy.
The lesson is, if you want to get rich don't reduce the cost of your labor force, increase the value of your production.