At the late stage of a paradigm, all of the problems bunch up into one meta-problem.

But because each problem seems unrelated and small, you don't realize that there's a single thing that could solve all of them at once.

But when the paradigm shifts, it's an explosive unlock.

Paradigm shifts require solving multiple problems all at once.

So they're hard to make legible before they happen.

That's why they seem to explode onto the scene.