Writers are always instructed to make sure everything within the pages of a fiction manuscript advances the story. While it's one of the better "suggestions", aka "rules", it too is not foolproof and inarguable.
Stories combine a multitude of factors. Characters, locations, sights, sounds, smells; literary, action-packed, ordinary, extraordinary, fantasy, supernatural, historical, criminal, styles and genres. If the above rule is applied religiously and unbendingly, the author will produce an Ernest Hemingway replica. And while some professionals love Hemingway, many readers do not. As I've said repeatedly about Hemingway, he was a terrible writer who told great stories (with the exception of The Old Man and the Sea).
I would guess editors are as diverse as writers which is a giant reason for using one who complements and understands the writer's style. Differing opinions as to what "advances" and enhances a story present significant conflict.
I enjoy details in a story. I like to read them and I like to write them. They don't have to be included for the sole purpose of contributing to a story but instead to provide a wider vision of plot, scene, etcetera. I like characters and their sometimes superfluous reactions fleshed out because to me it tends to make them more realistic.
If you've ever read a Tom Morrisey novel, you will generally read a lot of technical information included with his touching and action-centered literary style not usually found in this rare combination. Traditionally, you get one or the other, but Tom has a unique way of bringing them all together. One of my favorite novels is Tom's In High Places, the touching story of a father and son who climb rocks and experience the death and grief of losing wife and mother, and the son experiences first love while trying to figure out why his mother died the way she did. Meshed with the hard adjustments to being without the woman they loved, we feel the sorrow, the growing morose mood of the father, and all the while we're also reading about the technical equipment and instructions for rock climbing. Tom's a rare breed of author.
Authors can go off on tangents, and this rule is designed to restrict their falling in love with their flair for words. The evil red pen of editors can easily kick those extraneous words to the curb without even flinching, while the author of those precious darlings sits slumped in a chair bawling over the marked up manuscript. The decisions to keep or extract words should make sense and not feel like a death knell to the story by the author. Again, finding a compatible editor is critical for the storyteller.
The point of all of this is to tell a good story - to present an entertaining piece of work for readers to enjoy, to immerse themselves in a tale that accomplishes the desired results. It's important to note readers are as different as writers. Their fickle tastes cannot be served by obeying or disobeying every rule known to authors. Story will trump writing in most cases but not all. The idea is to give the best audience for your work the dual satisfaction of a good story and good writing. No easy task but worth the effort if you're a writer. And that's the point after all.
Father, apart from you, we can do nothing. Thank you for sharing your creativity. May we use it the way you intended. In the Name of Jesus, Amen.