Remember old Freytag and his pyramid? He designed a diagram to help writers visualize how their story lines need to progress. It's just a simple triangle that illustrates how we should move from the beginning of our tales . . . all the way to the end.
See - it's very simple and straightforward.
It can really help writers working on sharpening their skills, to see how to structure their stories (or novels). The problem I've been finding is that people seem to be taking it too literally.
Think back to when we first learned about the pyramids of ancient Egypt. That's how we pictured them - with straight sides. It wasn't until somewhere in high school or college, when we found out they were really built out of large squares of stone - and looked more 'chunky'.
It's not quite a stack of square blocks. Instead, it shows how the plot builds; then there's a bit of resolution; before the plot continues to intensify. The reader needs little breaks - little respites - sprinkled in the mounting tension. Equally, once the main obstacle has been met and conquered, you want to gently present resolutions to all the subplots; and perhaps, throw in one or two new obstructions. Otherwise, you let the reader down too quickly and that leaves them unsatisfied.
Leaving your readers hungry is not the same as leaving them wanting more.