User blog comment:Rupert Giles/Layout Changes: Breakpoints and Typography/@comment-4189499-20150520014724

Just an FYI to many of the people complaining here, when Wikia is talking about mobile devices here, most of these devices are laptops. Yes, laptops. Probably one of the biggest groups of computers. Certainly, among the people I know, the vast majority of them use laptops to access the internet the vast majority of the time. Laptop screens, tabltop screens (tablet/laptop hybrid), and tablet screens are significantly smaller than desktop screens, at least when comparing to the screen sizes people are talking about here. And don't go on about screen resolutions, as I can prove that the amount of pixels on your screen doesn't in fact control which layout you're seeing but rather there is obviously a more complex algorithm going on which takes in to account number of pixels, actual screen size, and browser zoom. My Surface here has a 2160px width, but is only about as wide as an A4 sheet of paper (don't know the exact dimensions), and as a result see one of the middle width displays. For somebody viewing your wiki on a screen the size of a piece of paper, not just people viewing your wiki on a screen the size of a couple of post-it notes, the display used to look significantly different from what a poster-sized desktop saw, and if editors didn't take in to account the fluid width and instead added fixed widths to their elements, tables could go way off pages and full-width images would be cut off and other such problems. In the other direction, I often found when designing things such as main pages or heavily illustrated help pages that what I made, which looked amazing on my paper-sized screen, looked rubbish when zoomed out to show what a poster-sized monitor would show because of how sparse everything was. By making the width the same, editors on medium-sized devices can know that their edits won't look like crud on larger screens. It may take some time to make sure all pages look good at the new widths, but once they are good, you can guarantee they will stay good!