In times equally long past I would have guessed it smart phones became a thing: they'd probably run something derived from Windows CE or be a tad Palmy. Meanwhile what I would have wanted back then would probably had looked something like PDAs from Sharp and Nokia.
Today, be it for better or worse: Android is insanely successful. It is to mobile what Windows is to PC in just about every sense of the word. Except it grew up with underpinnings built around Linux and Java rather than DOS and C. It also has had the benefit of hindsight: as those creating it came from a world populated by Windows and Unix based systems.
Microsoft is doing pretty well today. Hell they've even made some nice software and services. But they are dead as the platform for mobile. Want to use Microsoft things on the go? Your phone runs probably Android. If not well it sure won't be running a Microsoft operating system!
For about the last five years or so, I've kind of wondered if in about another thirty years: will Android eventually overtake Windows. Much as Microsoft pretty much became the gold standard as Unix vendors fiddled and burned.
One thing is for sure: the Linux kernel ain't disappearing anytime soon 😜.