What if Linux took over the world and basically no-one noticed?

The obvious answer is, of course, that the vast majority of *NIX-based systems most people use are propriety, i.e. they’re Android and Mac-/iOS, meaning the *NIX community itself generally doesn’t “count” them. And the place where most “traditional” *NIX-type OSes are used, i.e. server infrastructure, is generally fairly inscrutable to non-technical types. But the reality is still the reality, and it’s actually Windows that’s the weirdly different hold-out operating system in the ecosystem.