A friend once questioned why anyone should read anything other than the Bible. He was talking to a literature major in college and seriously wanted to read only the Bible. My guess is he isn't aware of the purpose of art.
The reason to read more than the Bible is that God created the world and people, both of which are described or shown in art. We learn about or see the beauty in his creation when we view and create good art. Details of life are highlighted so we can see them clearer and appreciate them more—God enjoys us enjoying creation and learning or reflecting on its complexity. Sometimes we focus so much on one thing we forget to look around and appreciate what's around us.
Also, God wants us to communicate with others, and one way to communicate is through art. Art is a form of communication when it's shared with others. Through art we see what others are saying and reflecting on.
The key is that what we view and how we think about and create art should be shaped by the Bible's principles of what is good.