Why would you say it's important to have a happy ending in ""formula fiction"" (like ""A Secret Sorrow"") ?

'Formula fiction' is the literary genre that has been given this name in a derogatory sense to condemn it for being deprived of originality, thus, often regarded as the 'predictable genre' due to its obsession with the reuse of the content, plot, and characters. The 'formula fiction' like "A Secret Sorrows' is not compelled to have a happy ending yet it dealt most commonly with "romantic comedy" which aims to bring relief to the audience at the end. 'The Secret Sorrow' opens with the dreadful and tragic past of the Faye the protagonist and concludes with finding her true love and find an escape from her haunting past. This genre follows a formula that provides the audience too, an escape from the obstacles and darkness of their real-life and find solace in their romantic world for some time.