Epic poetryis addressed to a cultivated audience, who do notneed gesture; Tragedy, to an inferior public. Being then unrefined, it is evidently the lower of the two.
This feels like a very classist statement. He's saying that people of lower classes are too dumb to understand the "refined" "complexity" of Epic Poetry because it doesn't include aids like gestures and spectacle. Given my basic understanding of class systems in Ancient Greece, I get it. But can you imagine someone saying this today?