Sadly the talent pool for public service sucks in general, because the jobs tend to suck by nature and we don't go out of our way to promote public service or recruit anything above the bottom of the barrel.
Multiply that times a half-century of copaghanda and the drug war pre-selecting law enforcement candidates by willingness to fuck up other citizens lives over literally nothing, and here we are.
Even if we started today with an Apollo Program level of commitment to rehabilitating our society's public service talent pool, it would take a generation to see the results. But we're not even starting, so it'll just get worse.
The best argument I've read is that nobody in their right mind would want to be in a position of authority. You're constantly criticised by everyone around you and receive hardly anymore compensation than rank and file workers. It's why sociopaths and power hungry narcissists tend to fill authority positions.