One down side is that most of us don't know how to speak persuasively. Piling on more words feels good and doesn't work.
Sure, there are subjects that require a lot of words to express. That's why you go to school for years to learn how to do math and science and stuff. But they have to be the right words, and that takes a lot of time to craft.
Luckily, there are always cats to help explain things!