There’s still large gaps that need to be filled.
> people want to differentiate on style in ways that go beyond a CSS skin.
And the reason this is a problem is due to shortcomings in current widgets, which is part of what I was getting at. There’s no technical reason why everything can’t be skinned with CSS, as we’ve seen with modern versions of GTK+ which rely on it entirely for styling. It’s fixable, but there’s little work being done to actually fix it.