Dialogue isn't usually the vehicle for momentum in story. Its purpose is to deliver undercurrent, reveal what's not being said. Often, dialogue will let us into the underworld of a character, showing whatever is hidden and secret. Not because this is stated in the dialogue itself, but because it's communicated by the tags (he said, she said) or lack thereof, by the pauses and beats, by the dialect or tone.
In thrillers, the dialogue contributes to pace. The dialogue kicks things into gear.