Why is figurative language used in writing

Using figurative language is an effective way of communicating an idea that is not easily understood because of its abstract nature or complexity. ... Writers of prose and poetry use figurative language to elicit emotion, help readers form mental images and draw readers into the work.

dramatic irony occurs when the reader/audience knows more about a character's situation than the character does. the one main effect is that it gives the reader a sense of superiority, or detached superiority. the reader not only seemingly discovers what is revealed, but feels superior for doing so.