How does subject verb object facilitate clarity and ease for the reader?

Simple: I understand your Words. (Subject-pronoun verb object)

I could say, "I understand" but only if there is context about what I understand.

Without the verb or object in the above sentence, there would only be "I" which is a good thing to be, but no one will be able to understand what "I" want to say or write if I don't add a verb and object to my "I".