On the other hand, it made webpages way less flexible.
Like yesterday (i have the browser not in fullscreen, for reasons) on my 16" fullhd notebook, webdev couldn’t imagine that someone would use his site in a ~1000px browser window, sidebars left and right, the main content about 20 characters wide squeezed inbetween. So i pressed f12 and deleted the sidebars. But the content was still 20em wide, because of flexbox.