A picture is worth a thousand words.
Diagrams and illustrations make instruction manuals easier to follow.
Gestures can make speech more easily understood.
Metaphors convey ideas it would take paragraphs of words to match.
Shorthand communication. If there’s a quick and easy way to get the picture, feelings, from my mind to yours, it’s my job, even obligation, as a writer, to use the most effective method.
Clichés are shorthand, just as images are.
And both require judicious use.