I&#x27;d say Windows is a bit more fragmented UI-wise than Linux, even if you remove Qt from the conversation entirely. There simply hasn&#x27;t been a strong notion of &quot;this is how a Windows app looks&quot; since the, say, Win 98 days between multiple different generations of MS-blessed designs, the skin-heavy era and a myriad of toolkits. The classic &quot;Windows app&quot; design in my mind is Notepad, and few apps look like Notepad. I admittedly don&#x27;t use Windows heavily, but the few apps I use occasionally inside a Windows VM or on the dual-booted Windows on my laptop all sport widely different UI appearance:<p>- iTunes (built on a port of some of Cocoa I think)<p>- Spotify (custom UX, also on Linux - using Qt - but I don&#x27;t bother)<p>- Steam (custom UX, own toolkit - also on Linux)<p>- EA Origin (custom UX, made with Qt)<p>- KakaoTalk (custom UX, I think using a native toolkit though)<p>- LINE (similar to Kakao)<p>- Telegram (custom UX, built on Qt - actually this runs fine on Linux, but I keep it in the VM alongside KakaoTalk because it&#x27;s the same use case)<p>- Firefox (custom UX, with native-ish theming by its own XUL toolkit grabbing stuff from Windows APIs)<p>- Chrome (custom UX, built on a custom toolkit called Aura with some Windows exceptions)<p>- Kodi (custom fullscreen UX)<p>All of these are apps with user numbers in the range of hundreds of thousands to tens of millions, and they&#x27;re all unicorns. (You may never have heard of KakaoTalk or LINE, say, but both have 50+ million desktop installed bases.)<p>Some of the above (Telegram, Firefox, Chrome, Steam, Spotify) show up on Linux just the same, no better or worse. Outside of that, most apps people actually use on Linux:<p>- KDE&#x2F;Qt apps, which import a lot of standard structure from kxmlgui and DE settings (e.g. dialog button order, standard dialogs) from Qt&#x27;s QPA plugins<p>- Gnome apps, which follow a strongly defined HIG<p>- Non-Gnome GTK+ apps imitating the Win98-style HIG for the most part (which overlaps a fair bit with the kxmlgui standard structure)<p>Sure, there&#x27;s a long tail of other toolkits on Linux (just as on Windows), but my argument is basically: Going by the most-used apps, Windows and Linux suffer this problem (if you consider it one) to a similar degree, but Windows slighly worse because outside the apps showing up on both platforms, the remaining popular Windows apps are more fragmented UX-wise than on Linux with its three broad categories.<p>Heck, Windows 10&#x27;s <i>bundled</i> apps are fragmented UI-wise to a much greater degree than any competing offering due to the classic&#x2F;Metro divide.<p>It&#x27;s an utter mess. An interesting question is whether this messyness hasn&#x27;t had some benefits (like allowing app designers to iterate and innovate individually, with no concern for following a system HIG, allowing the overall platform not to fall behind the curb). But arguing the mess isn&#x27;t there is very strange to me.