Please help.. How does writing authentic dialogue help a writer’s story?

Dialogue advances the plot and makes characters seem more real.
Dialogue allows writers to include more sensory details than other kinds of narration.
Dialogue easily reveals setting, orienting readers to the physical world of the story.
Dialogue adds length to stories that would otherwise be very short.

Question

Please help.. 	How does writing authentic dialogue help a writer’s story?
 	
	Dialogue advances the plot and makes characters seem more real.
	Dialogue allows writers to include more sensory details than other kinds of narration.
	Dialogue easily reveals setting, orienting readers to the physical world of the story.
	Dialogue adds length to stories that would otherwise be very short.