>and you are not supposed to enjoy it if you are.

Hard disagree. Prison is the one you're not supposed to enjoy, jail is the place you use to keep people BEFORE they are judged.

A jail should limit the people held only as much as needed for the safety of the public and the handlers, but no punishment should be inflicted because no one's a convicted criminal (yet).

And in any case, prison should have a strong component of making the guilty person fit to live among others. A person that's been made to sit still staring at the wall for all their waking life for years is a person I definitely don't want as a neighbour, because there's no way they come out of that sane.