Everyone knows that, but no one really stops to look at why. Certainly indeed fear is scary because it threatens not so much death, although the threat of destruction is a part of it. Mainly it's scary because it threatens impotence. And even scarier is feeling that pain and not dying, and therefore having to live the rest of your life with that. But more than that, fear threatens the withdrawal of affection.
Fear threatens the exposure of the Dark side of self.
Fear also threatens the exposure of the Light Side of self, the positive qualities that people have that they've similarly learned to tuck away. It's what psychologists call the Shadow, the Dark Shadow and the Light Shadow. Fear threatens to expose them both. Fear threatens also to produce or generate destruction. And fear blackmails.