Besides all of your other excellent points, I wonder if it ever occurred to your friend that the people who can afford to hire their own police are a tiny percentage of the elite wealthy.

Almost no one else can afford to hire police. In fact, almost everybody else gets paid so little that the elite wealthy can pay them a pittance to do security work.

People who talk about not needing government are people who are wealthy enough not to worry about it or who aspire to being wealthy enough not to worry about it.

Good government takes care of all people in society, not just the rich.