Contemporary writer's work is categorically defined by word count. The numbers blur a bit between how many words constitute a novel, a novella, and the relatively new novelette. Lines are not hard and fast, but there are generally accepted ranges. Roughly speaking, a novel is over 50K, a novella begins at 20K, a novelette around 7.5K, and a short story squeaks in under the 7.5K mark. Flash is typically under 1K and then broken down into several smaller categories. The greatest breakdown I came across is in an article by the Author Learning Center where they not only define flash and micro flash, but there are categories for smaller pieces called a dribble and a drabble.
Fiction is broken down into sub-genres, and each sub-genre has a designated word range. Many writers strive to reach genre defined numbers. Between writing, editing, re-writing, and re-editing, stories may take years to refine. Many writers never finish their books, even though they have wonderfully crafted stories. Editing is much harder than writing, and reaching specified word counts can be daunting. There is prestige as a writer to say that one is writing a novel. Say you are writing a novella or novelette, and the reaction is not the same. Some stories need a plethora of words to develop the character and for the plot to unfold. Others do not.
Is a novel of 80K words necessary? Maybe, maybe not. The question is, how many words does one need to tell a story. If more, so be it. If less, that should be ok as well. The substance of the story and development of character and plot are of importance. Flowery fluff to fill in space does not an interesting novel make.
As a writer, I want to be unencumbered by how many words need to be on a page. When a story idea comes to mind, I tend to pre-define its destination. It hinders me from taking the words on their journey. When I meet with my writing group, I love when each one says they do not know where they are going that day. The more I write, the more I let the length of each piece go to where it wants to go. Does it make an arc; does it have a beginning a middle and an end? Be it flash or a novel matters not.
Did Shakespeare count his words? Am I barred from being a Bard, if I do not achieve the word count?
Fitzgerald, Steinbeck, Bradbury. and Orwell are called novelists. The Great Gatsby, Of Mice and Men, Fahrenheit 451, and Animal Farm are some of the greatest novels ever written and each one clocks in at under 50K words.