Also I don't understand how doubling it makes it simple, when the screen size is not doubling with it. If the scaling is the same then you get smaller icons. If you double the scaling to match the doubling of pixels, everything is bigger and there is no extra space. Unless I'm thinking about this wrong.
You're not thinking about it wrong. Doubling again does not help. If the physical screen is not twice as big, everything on it will be twice as small to touch; lots of screen real estate, but very hard to use. Or, you double the dimensions of your assets and everything is easy to use and very sharp, but you don't gain any real estate; like the retina iPad, it's beautifully crisp but still no more on screen room than an iPad 2.
If the point of a bigger screen is to have more screen real estate, the resolution needs to increase in a way that yields a similar ppi while on the larger screen. That way the controls maintain their physical size but we getroom for more of them.
If the point is just to help people who struggle to see small icons and text, the resolution should be unchanged or dimension-doubled for the larger screen.