I doubt that access to unskilled, unmotivated labor is really that profitable for most modern industries, since it ensures low productivity and displaces business improvements. The reason it works economically is that the taxpayers are paying for prisoners to be fed, clothed and housed, and so the labor can be bid out for very low prices, which makes the lack of skill and motivation break even.
> access to unskilled, unmotivated labor is really that profitable for most modern industries
It depends on how we qualify "modern" industries, but there's definitely a market for unskilled warm bodies. Recycling triage could be an example of that: the result is simple enough to assess that you can set a dozen of people on a line and adjust reward/punishment depending on the results. And it's definitely a modern problem.
The other aspect: while there will be better ways to do it, it won't beat the price of "slave" as long as there's no other risks in participating in the system.
In a very dark way, it's pretty hard to beat "almost free" through sheer technical advancement.
