This is not relevant. The layers are not really built on top of each other in that way. Windows is mostly just a collection of libraries which do important stuf

This is not relevant. The layers are not really built on top of each other in that way. Windows is mostly just a collection of libraries which do important stuff. If you did not have this libraries, you'd have to write the libraries. So this is not a layer you can remove, it's an essential part of the application. Things like the Java VM are a real layer, but things like MFC (which chrome does not use, it uses WTL) do not really slow things down or act as a real layer. They compile down to the same code as if you were to do this by yourself. And anyways, what's the point? We should stop writing web apps?