Those who propose that our scriptures are best understood as “inspired fiction” almost inevitably frame the questions wrong.
The question is not whether fiction can be inspired. Jesus’ parables, the Allegory of the Olive Tree, many of the Psalms are obvious examples of inspired fiction.
The question is: Is that what ALL scripture is?
The question is: Can fictional stories of Jesus’ resurrection provide us with eternal life?
The question is: Can a fictional Book of Mormon demonstrate that Jesus is the Christ?
The question is: If the Book of Mormon is nothing but fiction, why would Joseph Smith lie about having met Moroni and have received golden plates?
The question is: If God can reveal authentic truths about the past, why would he inspire Joseph Smith to produce inaccurate and false stories about the past?
That some fictions might be inspired does not mean ALL fictions are inspired. That some inspired things might be fiction does not mean ALL inspired things must be fiction. That God might choose to reveal a truth in fictional poetry or narrative does not mean God cannot, has not, or will not reveal authentic truth through and about history.
People advocating that we jettison belief in the historicity of the Hebrew Bible, the New Testament, the Book of Mormon, and the Pearl of Great Price need to engage these questions, and understand the obvious implications of what they are proposing.