A truism in writing: both stories and essays tend to be terser, more edifying and more gripping if the point the author is making is demonstrated through example and experience rather than explained. This is a guideline frequently invoked by writing teachers and one that I am inversely illustrating right now! Wouldn't you rather i told a little story about how this rule helped me conquer the world?

Also, filmically, showing is considered more authentic because it allows the subject to speak in their own words (or actions, as the case may be). Of course, this standpoint does not take into account the massive sense-making power of the filmmaker as editor and author of the story told with this "authentic" material.