Yes.

For anyone who thinks this is hyperbole, ProPublica has done excellent work investigating how lenders use the court system to imprison Americans who can't pay back their debts: https://www.google.com/search?q=propublica+debtors+prisons

Debtors prisons are bad but of course that’s a separate issue.

> Yes.

By this logic, slavery should be legal, because people should have the freedom to sell themselves into it (for instance, to purchase medical care for a loved one).

Huh? I literally said the person would be selling themselves into slavery, which means becoming chattel property with no rights of any kind. That's nothing like a non-slave "working for a predetermined rate," because those workers still have rights since they're not property.

Yes.

Sometimes it can be beneficial to you to remove your own options- if you can prove to others that you've removed that option.

For example, look at the prisoners' dilemma. If both prisoners were able to commit, ahead of time, to not defect, this would be better for both prisoners. By removing a choice, and proving you have removed that choice, you actually get a better outcome than what would be possible if you could choose to defect.

This applies in asymmetric situations, too, like contract negotiations given a significant imbalance of bargaining power. It can be beneficial to the worker to, say, prevent themselves from ever agreeing to work in unsafe conditions, even if the boss offers extra pay for it (which the worker might want).

Thus selling organs, or selling your children to "adoptive" parents. It's not about somebody else having "authority"- it's about you intentionally burning bridges, provably pre-committing, removing the "choice" to do things which, on a societal level, could be harmful.

Who better to decide if that is beneficial or not than the worker themself?