Think about who's harmed by supply side constraints and artificially high prices.

The government isn't hiring cosmeticians or plumbers or whatever in bulk. It's hiring cops. So it wants them to be cheap. The fact that they're scary thugs who could potentially be dumb and hot headed is a feature. Scares the peasants into compliance. It's a force multiplier basically.

On the flip side the government is happy to enforce supply constraints for any random trade so long as it's not so absurd that it hurts the legitimacy of the government by making it look corrupt and making people resist it.