The niftiest turn of phrase, the most elegant flight of rhetorical fancy, isn't worth beans next to a clear thought clearly expressed.
When writing or speaking, we may get carried away with complicated words and sentence structure. It sounds sophisticated. But is it all that sophistication if a clear meaning was not communicated to the reader or listener?
In successful communication, the goal is to transfer one of our thoughts into the mind of another is our fancy words and terminology detract from the goal, they are worthless.
So speak and write clearly when trying to share thoughts with others. We don't need to use complicated sentences to describe our ideas.