Why do poetry, fiction, and drama matter?

Literature is a reflection of the human condition, and it also provides a model for human behavior. What we call "drama" usually has as its basic formula the placement of ordinary individuals into extraordinary circumstances. Reading about or watching people undergo tragedy and difficulty is a way to help us develop empathy and also receive inspiration to deal with our own troubles. 
Literature, including plays, novels, and poetry, is also often a vehicle for commenting upon society as a whole and drawing attention to social problems. As far back as Shakespeare's day, we see portrayals of issues like racism and anti-Semitism in Othello and The Merchant of Venice. Well before Shakespeare, the ancient Greek dramatists used humor to point out the folly of too much military activity (in Lysistrata, which also had an interesting remake in a recent film by Spike Lee). The Greek dramatists also provided profound lessons in human nature that later became part of contemporary psychiatric theory (as with Freud's theory of the Oedipal complex based on the Greek character Oedipus).
Many poets and fiction writers have offered poignant and powerful commentaries on contemporary social issues such as racism and sexism; for example, Langston Hughes, James Baldwin, and Alice Walker are but three writers whose work have helped illuminate the experience of being black in America. Sylvia Plath, Adrienne Rich, and Nikki Giovanni are poets whose work is considered part of a canon of feminist writings that is important for understanding women's struggle for equal rights.
https://www.crmvet.org/poetry/poemhome.htm