Curious that you mention fast, because it is something Electron definitely fails on.
Web apps are for my already installed browser.
QML is as pretty as the design skills of the developer, just like CSS. And better because the full power of the graphics stack is available to the developer, down to pixel perfect graphics, unlike CSS where Houdini still isn't a thing.
Any native application is faster than a Electron based app. It is quite trivial to achieve.