I mean the cops are also doing the bidding of the obviously corrupt minister, with the exception of Kingsley Shaklebolt, who is an undercover agent of Dumbledore.

The entire concept of “fighting dark magicians hurr durr” is never put in the context of how subverted or openly on the side of dark magicians the ministry of magic is. Sometimes it is hinted at, like how Arthur Weasley is dissapointed that the department for the missuse of muggle artifacts is chronically underfunded and wizards that like to play harsh pranks and torture muggles aren’t punished properly.