You can't possibly be serious, right? So what is the point of police patrol? Adjusting police presence in different areas? Community initiatives? Prevention is definitively a key component of modern policing at least in every city and country I have lived in.

If that isn't the case in SF I'd say then that they have obviously failed on all levels at enforcing the law. Not to mention, punishment is definitely not the job of law enforcement.

Yes and no. Law enforcement's job is in its name. It is to enforce. It is to be the visible arm of otherwise ephemeral law that we agreed upon as society through, hopefully, some sort of consensus. And yes, their presence also serves that purpose, but they are not there to punish ( although I am sure we are all tempted to tip scales at times ). That job is typically the domain of another public institution.