[raquo]

Being relatively low level is a feature. HTML / CSS / JS are languages, not frameworks. One liner modals are not a feature a language should have.

If you want, you can make a framework on top of it that will behave like a desktop UI framework with standardized elements and behaviours. There are plenty of such frameworks actually. But not having to use such a framework is nice.

Besides, the current browser environment has been historically heavily optimized for websites, not desktop apps. If it became a popular choice for desktop app UI we'd have developed more appropriate features for that use case.

[cm2187]

Why do you call html and css a language? To me it’s a UI framework very much like winform, wpf & al.

[raquo]

Because it's a markup language, and a style definition language respectively, so HTML / CSS lack the high level features and components found in desktop UI frameworks such as Cocoa (standard buttons, lists, file explorers, image grids and such). Building a HTML / CSS UI is done from the ground up with basically nothing more than completely unstyled boxes, in contrast to composing higher level components.

On the web the role of desktop UI frameworks is distributed between third party frameworks such as Bootstrap which is great because those are optional.

I haven't worked with the windows frameworks you mention to compare directly to them.