The problem, as with so much writing advice, is that it's a matter of opinion as to whether any word or scene serves the story. Even identifying what the story is, may be a matter of opinion*. Part of the writer's art (with some help from a good editor) is in their choice of what matters to the story they are telling**.
* Some years ago I saw an ultra-short animation clip on YouTube that cut Lord of the Rings down to essentials: the hobbits hitch a ride with some eagles and drop the ring into Mount Doom - the end. And why not? If you view this as an adventure about destroying a ring then cutting out everything that doesn't directly serve that end leaves you with something like that clip. It's like saying every such tale is a variation of the Hero's journey. It might be vaguely true but it's not all that helpful. No one wants to read tales couched in such terms, we want the excess words and scenes.
** As opposed to the story you might rather be reading 