Some dialogue can indeed be helpful to convey character's emotions, but it's not the only way.

The kind of dialogue that isn't helpful is dialogue with Onix. Trust me, I've been there...

Once I was asked if I was a girl (I'm not) based on how much my stories are focused on emotions (and since focusing on emotions is indeed what I'm trying to do, I take it as a compliment showing that I succeed). Onix's opinion? Apparently my characters are autistic and incapable of emotions, never mind that pages upon pages are dedicated to expressing the characters' emotions. Apparently my characters have no motivation do to anything, never mind that pages upon pages are dedicated to their motivations. And apparently since my characters have no motivation to do anything they will only lie in bed until they starve, because they can't even be bothered with getting up, never mind that it's the exact opposite of what's actually happening in the story.

My conclusion, seeing how fiercely Onix would come out of his way telling blatant and outright lies about stories right into those stories' author's face just to label other's characters autistic, is that it must be a defensive reaction to deny his own autism. Because what else can such an utter disability to perceive characters' emotions be? Either that or he's just a troll, but I wouldn't want to think bad of him, so I'll settle on autistic for now.

Anyway, the bottom line is: better spend your time productively writing more stories than pointlessly waste it trying to futilely argue with Onix.