I try to avoid narrow, limiting definitions of what literature is, what it can be used for, and how one ought to approach it, for two clear reasons. First, approaching literature is primarily an individual activity, and the great diversity of humanity must call for multiple subjective approaches to literature. And second, there are so many potentials for literature, it seems harmful to try and limit those uses.
I found this passage from John Fowles' "Notes on an Unfinished Novel" particularly articulate on my thoughts:
"[Alain Robbe-Grillet's] key question: Why bother to write in a form whose great masters cannot be surpassed? The fallacy of one of his conclusions--that we must discover a new form to write in if the novel is to survive--is obvious. It reduces the purpose of the novel to the discovery of new forms, whereas its other purposes--to entertain, to satirize, to describe new sensibilities, to record life, to improve life, and so on--are clearly just as viable and important."
Fowles was an innovative novelist with a strong grip on manipulating form, particularly in The French Lieutenant's Woman. But it doesn't appear that Fowles considers innovation of form primary to his art (he suggests later in the same essay that his novels are "based on more or less disguised existentialist premises"). Indeed, there are purposes to the novel beyond innovating the form of the novel, and Fowles only describes a few.