The definition of focusing and simplifying is so great. Focusing on key areas that have the biggest impact helps keeping things moving. It feels simpler, but it does not make the problem simpler.
A complex problem cannot be simplified.
If you can simplify it, then it isn’t a complex problem.
You may choose to focus energy on a key leverage point, or establish one or more enabling constraints. To make progress, you may choose to selectively ignore things, blur your vision, or think in broad strokes. These approaches will reduce cognitive load and will feel simpler. But they don’t leave us with a simple problem.