I do think fiction is essentially about telling a good story. Of course there is plenty of fiction that isn't about that at all. Some books are all about the words.
A good book is of course about both the story and the words. Some writers get that beautifully, some not so much.
I read something today that had me thinking about words and word choice....well maybe it had me pondering. I love interesting words and the way certain words feel when they roll around on your tongue. I love a bit of onamatopeia.
Don't you love how some words some up the way you feel? Wretched. Bereft. Forlorn. Effervesccent. Spent. Bilious.
Or words that sound like they smell - fecund - and words that make your face form the expression that matches the word like rancid or sound like they look such as plump.
Of course that doesn't mean that you should use those words in your writing. "Put that plump persimmon in the bin it's rancid smell is making me bilious." That might be over kill.
As much as I love words- and I do wish more people would use interesting words in everyday conversation, not only so I don't look like such a weirdo but so that our language doesn't continute to shrink they way it seems to be these days - if I have to choose between a cracking yarn or beautiful prose that meanders no where, I will choose the former.
Despite the beauty of the language in some books there are very few that have sentences and phrases that stay with you days or weeks later. A good story that touches your heart and takes you on a journey, the memory of that can linger for years.