Except for a few of the prisoners that got filthy rich through their crimes.

In a country led by oligarchs and kleptocrats, where even the military is super corrupted from top military general all the way down to mere squad leaders, money always talks. As long as one can pay a sufficient amount of big bribes, he can walk away scott free and makec a *lot* of "behind the scenes" deals. Or be relatively treated ok (or even with favors) while remaining in prison.

This does't include those that were super duper filthy rich: those just bribed their entire sentence right away in the first place, and never went to prison.

But the "merely" criminally rich might have preferred to hang on to their illicit cash secretly, while remaining patient and in prison until they get out and then live well, because bribing their wait out prematurely would mean that once out they wouldn't be rich anymore. But now that "choice" has turned into either keeping your secret riches but going to the front and probably die, vs freedom and relative safety albeit not rich anymore.

But that probably applies only to a few. Most prisoners just would not have the money to make those kind of "deals".