Documents, in the real world, are full of layout that has been difficult to replicate in CSS. And to counter your point more directly CGI and the concept of web

Documents, in the real world, are full of layout that has been difficult to replicate in CSS. And to counter your point more directly CGI and the concept of web applications existed before CSS 1.0, so there was already need for application-style layouts when CSS was being designed. Flexbox isn't the answer either. I had high hopes for it and I'm in the middle of redesigning a web application UI using Flexbox for layout, and I still can't do some basic things like have an overflow:auto content area that expands to fill the space between a fixed left-hand nav panel, a variable-height fixed header, and a fixed footer. I'm still stuck with a bunch of javascript and a window.resize event handler to measure some heights and adjust the sizes of my containers. Maybe the upcoming CSS grids will work, but it'll be another couple of years before support is wide enough for me to use them. EDIT: I also wanted to say that I've learned xaml in the past few years, and that's absolutely not the direction I'd want CSS to go.