Dude I fucking hate those Linux ubernerds, and think that “looks shitty” is almost a Hallmark of your classic Linux application, but… you have no idea what you’re talking about. (…Also I don’t think you know what a “kernel” is.)
“40 year head start” is one hell of a fallacy. As if MS and Apple from 1983 are meaningfully related (in this sense) to what they are and do now.
The fundamental difference, anyway, is cross-platform compatibility. What percent of Linux users even use desktop office suites and shit like that? The desktop world has been moving to the browser for 15+ years and both Chrome and Firefox are practically identical on every OS.
Linux has a long way to go, but the stuff you were listing is madness.