Windows actually used to be decent and fairly consistent, but I agree that it's gone to shit in the last decade. They botched scaling to HiDpi and fragmented their UIs in the sad attempt to chase convergence with touch UIs.
Majority? Not as I recall it. Some, yeah - famously winamp, which made it compulsory for music players (hence generating a river of tacky UIs). But in my world the majority of apps had the good old “top-bar-menu-icons, File menu, Edit menu, etc” format.