Did a report back in the 1980's while in undergrad school for one of my junk classes on recidivism rates in our prisons.  At the time, recidivism was around 75%.  Below is a link to a 2005 study which supports those numbers.  The issue is there is no separation between punishment and rehabilitation.  So, they babysit the prisons, letting them network, bring drugs into the prisons, while making them go to rehab programs where they promise to be good but will do nothing of the sort.

Our prisons and law enforcement have turned into a big-government business, where it's failures are swept under the rug while the government keeps asking for more money that does nothing more but create more prisons and employees in the system.

This guy will be housed for free for a few years, then be back out on the street selling either more garbage or hard stuff.  And then he'll go through the system again.

https://www.bjs.gov/content/reentry/recidivism.cfm