If covers are supposed to capture the intricacies of the book’s information in a single communicative visual, then covers that use iconography copyright that function as their official mission statement. Their basic - albeit deceivingly easy - graphic language doesn’t make for the type of cover which you’d pick up https://medium.com/@Self-publishing-on-Amazon/how-are-book-awards-and-contests-beneficial-to-authors-377d08495e52