The comparison to desktop native is interesting because you could also just not style everything to hell with css and...there you are, you are native styled with the web
The default style for the web kind of sucks though, so that's a bit of an issue. It also doesn't include a rich set of "widgets" that you get with Qt and GTK, so you often need to provide your own.
Also both Qt and GTK support styling with CSS by the way.
