I’ve seen it dozens of times, in my own work and that of my peers. After finishing three drafts of a story there are parts of it that are weak, sections that aren’t carrying their weight. They are easily identified by how they interrupt the narrative pace of the piece, how they pull the reader out of the story.
I tend to fixate on them. They are like splinters in the bottoms of my feet until I get past the following decision:

1. Cut the weak sections and flesh out what is left in order to fill the gap(s) they’ve left behind (if necessary^).
2. Go on to create draft number four and focus on those sections, trying to bring them up to snuff.

Option one is difficult. I like this harder path because that is where the risk and reward are greatest*, however, it is good to pause and give option two some serious thought. I’ve taken option two more often lately and it has worked out well. Why? At this point (draft three complete) those sections that are weak are not far enough developed to make the call that they should be cut** .
What I’ve seen over and over again is the weak sections (after another several drafts) become strong, even rivaling the strong sections. The result is a multifaceted story, one that has depth thanks to those passages that were “weak” and that I nearly laid out on the chopping block. I look back now and see that I was once willing to give up on what would become a significant layer of the story.

*See my post from June 6, 2012 or March 12, 2014. You need to be comfortable cutting material. Very comfortable.
^You would be surprised at how little deleting material from a piece hurts what is left.
**I heard recently on a NYT Book Review podcast that Jennifer Egan drafted parts of “A Visit from the Goon Squad” eighty times! That is mind boggling; however, it is much closer to the reality of crafting fiction than most writers can imagine. In any case, three drafts is only a start.