The main purpose of representative democracy is to free most of us up from the hard, tedious work of directly governing ourselves. We choose people to run our society for us, so that we have time to work, play games, and so on.
But it also has the benefit of publicly vetting a group of people who in turn select and oversee QUALIFIED EXPERTS to run stuff that requires real expertise, like how to lay sewerage.
The notion that law enforcement should be outside that system seems insane to me.