Prison crowding actually confounds just about everything that's positive about a correctional environment. Prison crowding leads to violence, bullying, intimidation, and gang activity. All of those things are related to the trade in contraband in an institution. Prison crowding is also dangerous for staff. Prison crowding also delays people's access and entry into programs. Again, it's just a capacity issue.
There is no positive side, no upside, to prison crowding. Of course, in federal penitentiaries prison crowding often leads to double-bunking, which is a significantly different issue from double-bunking in a provincial facility.
I don't want to get into a contest of who's running a better or worse system, but the average length of stay in a provincial facility is less than a month and a half, while the average length of stay in a federal facility is well over three years. If you're in a space that's designed for one person and you're living with somebody else and it's for more than four years, I think there's an order of magnitude difference. Of course, privacy issues and human dignity issues and even personal hygiene issues come into play, and all of that has a relationship to drug use and self-medication and contraband—and, again, to some of the other underground activities in institutions such as bullying, intimidation, or conscription of somebody else into an illegal activity inside the institution.