In 90% of cases, management consultants' job is to waste time and trick people into thinking something will change. Doing so allows management to avoid addressing the issues AND to lie and say they will/are. I've seen that happen twice in finance, once in software and 3 times in engineering.

McKinsey seem to have done that extremely well in this case. They allowed the jail to continue running, violence to continue, no extra funding was used and the federal regulator was assuaged. A new mayor avoided a costly, expensive, divisive, problem from a predecessor.

27.5m is cheap for that. That's why the mayor will hire them again next year.