Yes but I don't have a definitive map of who are the good ones, so we must treat it as a life or death situation and suitably defend ourselves in an interaction with any of them.

Why would I want cops doing that instead of social workers or teachers doing it?

No one becomes a cop because they want to be nice and help vulnerable people. Some might say they did but that is some coping technique. Being a cop involves exerting violence towards people who are vulnerable and desperate, and to become one you have to be fine with this. Some would say that this alone is enough to deem a person ethically dubious.

Even if one would accept the premise that society requires some degree of organised violence towards its members, one would also have to handle the question of accountability. Reasonably this violence should be accountable in relation to the victims of it, and police institutions inherently are not.

I think that we should also note that the other person above used "childishly" to denote something negative, apparently they don't think of kids as the light of the world and childish as something fun and inspiring. This is something that makes me quite suspicious of their morals.