Well using literary devices help a lot of you want to convey a specific feeling or message. For example, if you want to describe the emotion of sadness in a poem you may want to use repetition and say “I am so sad” several times through the poem to let the audience know you are sad. However, you might want to put your creative soul to work and describe the pain though allusions, simile or literal pain like “My pain is like when a toddler runs and falls down and scrapes his knee” or you can describe loosing your fav video game to someone you love like “My pain is very great; my lover left me forever with nothing to remember him by” the message is powerful and heart felt because people have experienced loss to be the same as heartbreaks. Also, sometimes using literal words is a good thing. Raw language makes for the best kind of writing because you convey powerful messages through writing what you feel or comparing that feeling to a crude situation you or someone else experienced before and know it hurts, makes you happy, sad, etc.
Hope this helps you If you need anything just message means I’ll be glad to help