55% of human communication is nonverbal.
Which means more than half of what you say is nothing but expressions and gestures and eye contact.
Which means if you use nothing but “he said” and “she replied” to tag dialogue, your readers are missing half the message. Besides which, body language is also an effective way to show tone without “telling” tone. For instance:
Epic-ness is all well and good, but without a personal touch, it can fall flat. We wouldn’t care whether or not Middle Earth fell to Sauron if we didn’t get to know Frodo and Sam along the way. It’s the little, everyday details that make us care; that show us the relevance of the big picture by connecting it to a close-up of the character(s).
There’s a scene in the Great Muppet Caper, in which Lady Holiday explains to Miss Piggy the backstory for the entire movie.
Miss Piggy: Why are you telling me all this?
Lady Holiday: It’s plot exposition. It has to go somewhere.