The “harm” is caused when people realize it is not moral for people to use violence against each other in the name of authority, and as a consequence cease to follow the commands of authority figures. No real harm is caused when this illusion disappears, hence the quotes. The power structure will disappear, and be “harmed”, but no human being will be.
Of course people are not mature enough to self govern yet. There would be chaos if all people playing the roles of police, military, etc stopped. That’s the primal terror and darkness we need to face individually, to confront the part of self that can do violence, and learn to govern it internally, and be the ruler of the kingdom of self.
When people are ready, these institutions will simply cease to exist, and be as absurd and illusionary any other superstition.