The written word is a unique medium. It allows the accumulation, concretization, and sharpening of one’s thoughts.
We can communicate ideas through speech and action, but these are not as direct an articulation. Consider that any brilliant speaker will be informed and honed in that craft by their writing, as well as the writing of others.
As writing is the essence of mulling over, of adding paint to the picture, so it is also of taking away excess. Poetry is allegedly the highest form of the written word. It’s expressive in part because it’s compact. It is compressed idea, emotion, intelligence.
Poetry is often revised and meditated upon, but it may also appear unfiltered. A captured crystalline figure from a mind with something to communicate. By this product, we may touch or vicariously approach genius.
Writing evolved from the spoken word, but is it an optional companion? To me, Wikipedia suggests otherwise. Writing enables iterative, high-quality idea snowballs like no other.
Perhaps we should think of the spoken word as evolving toward the written. It is the purest expression of language, more permanently spoken.