Right, this isn't news to me and also doesn't answer the question
Criminal justice reform has lobbyists against it, and also has a culture that is obsessed with punishment and bloodlust.
I think prisoner wages or the duties of prisoners can be addressed in some capacity, without maintaining a massive slave labor force. The circumstances around wording of the 13th Amendment, and subsequent case law may allow for redress against this outcome.
From the majority opinion in Bailey v. Alabama in 1910
> "The plain intention [of the amendment] was to abolish slavery of whatever name and form and all its badges and incidents; to render impossible any state of bondage; to make labor free, by prohibiting that control by which the personal service of one man is disposed of or coerced for another's benefit, which is the essence of involuntary servitude. While the Amendment was self-executing, so far as its terms were applicable to any existing condition, Congress was authorized to secure its complete enforcement by appropriate legislation."
So I see what the amendment says - prisoners can be slaves - but honestly, it may be as simple as that having never been challenged. Its probably why they are paid 85 cents in some cases, and only a handful of traditionally southern states paying them nothing.
In conclusion: there may not be public support for prisoner slavery, there may not be Congressional or state legislature support for prisoner slavery, and even if it got to the Supreme Court they might just lean on old case law instead of the plain text of the amendment.