I think the reason there are fewer 'incidents' as you put it, is that private forces are wont to escalate issues to state police forces. Some private security have severe restrictions on when they may or may not fire their firearms --due to not having the same immunity (indemnification) as state police forces.

The video presenter presumes people will follow rules --even violent people will follow rules --what force is going to enforce those rules 'not being on someone's property', for example. And unless all communities are run similarly, this will create 'outcasts'. Bad actors would just find another place to lay low.