I have no problem with having prisoners labour for their time. However, let them do chores that serve the public. Let them pick up trash and sweep the streets or pick vegetables on state farms. Work them 14 hours a day this way.
Just don’t have a system that incentivises convictions.
I tend to agree with that. Prisoners are not there to make profits for companies but to pay their debt to the public. Making them into free labor for business invites large scale corruption into the legal system that has enough already. They can be worked plenty hard without going down that road.