But in this case they are volunteers. They specifically applied to the firefighting program.
There’s certainly cause for discussion about the ethics, etc. but calling it slavery or involuntary servitude is hyperbole.
The 100+ page report at https://www.aclu.org/publications/captive-labor-exploitation-incarcerated-workers makes note of this:
More than three quarters of incarcerated people surveyed (76%) report facing punishment—such as solitary confinement, denial of sentence reductions, or loss of family visitation—if they decline to work.
Calling them volunteers is the hyperbole.
Anyway, give the report a read, yeah.
I think you’re conflating the general issue of inmate labor with the particular issue of inmate firefighters.
I think you’re ignoring data that doesn’t agree with your point. Inmate firefighters are inmate labor, my dude.