I think it's a cyberpunk thing. There's all this action, and it is fascinating and absorbing. It's all leading up to some major reveal and then -- the reveal is disappointing.

There is the concept of a MacGuffin: https://en.wikipedia.org/wiki/MacGuffin. It's the thing that sets a story in motion, but is actually irrelevant, beside the point. Like the Maltese Falcon in The Maltese Falcon. The important point is something else entirely, usually about human nature.

What The Diamond Age, and much cyberpunk do, is introduce the MacGuffin, but then they stick with it, forgetting that the MacGuffin is just a plot device. They mistake the plot device for the plot itself, like the whole point is to retrieve The Maltese Falcon. The MacGuffin is a point from which the story takes off, not the point of the story.