It never did. The point of the prison industrial complex is not to stop professional criminals but to deter the working class from making too much of a stink. This is also why prisons have to be squalid, inhumane places invested with bugs and where abuses by the guards are routine.

That's also why the judicial system is rigged to favor convictions and sentencing is disproportionately egregious for most crimes (e.g. possession).