He amazes the audience, first and foremost, because he finds a way for the audience to permit themselves to allow the magician to trick them- and that's why good magicians are also good storytellers. Just watch Penn & Teller, or Chris Angel, perform. Very different acts, but the same methodology.
The use of Narrative is not an evil unto itself. It is a tool, a powerful tool and an ancient tool, but a tool nonetheless and therefore one that can be abused--misapplied--and put to ends other than what it is intended to fulfill.
Through stories we relate to ourselves, each other, the world we live in, the past generations we come from, and the future generations we issue forth. It is our method of connection to one and all, working through emotions to communicate in manners that pure Dialectic can't achieve.
So, when someone perverts the power in Narrative to serve as Rhetoric intended to manipulate targets into conforming to the war-wager's will, it is one of the oldest forms of gaslighting known to Man. When exposed, it destroys not only existing trust but also the ability to trust thereafter. A people cannot maintain a community without a strong trust between the elders and the youth, great and small, rich and poor, past and present.
Civilization itself runs off trust, at all levels. Waging Narrative Warfare, therefore, is an act of barbarism and cannot be tolerated. It's not just fraud, it's corrosive and destructive of our ability to keep things running at a fundamental level- the sort we usually speak of using terms of faith and philosophy. This is why Narrative Warfare is an act of abuse.