Working on comics really helped me with learning how to be more concise and cut down on wordy dialogue and rely on using subtext to convey meaning instead of explaining things out in a lengthier dialogue. I think barring if the character's personality is someone who uses flowery language, you should try to convey the goal of the dialogue with as few words as you can while still preserving the personality of the character.
This segues to my belief that dialogue should serve a goal and communicate to the reader something. It could be conveying character personalities, relationships, worldbuilding, context, plot movement, etc. but the most important thing is that it has to be purposeful.
I would say an example of dialogue that has no purpose is something like this:
"Good morning x, how are you?"
"I'm good, how are you?"
"I'm good"
Unless the dialogue is part of some wider scene of two people being awkward with each other, this sequence wouldn't tell us anything about the characters, settings, or plot