That was my impression too. It added to the entire narrative and build-up of the movie. It was the edging that made you feel even more satisfied by the all out fight in the end. Plus it added to the human aspect of the movie. It's not just about monsters fighting, it's about humans witnessing and feeling helpless while monsters fight and destroy their cities as if they were playgrounds. Humans couldn't do anything at all, and the military futilely shooting their little guns at these gods demonstrates that even more.