Windows is still, for all intents and purposes, completely dominant.
Apple skated to where the puck was going, not where it already was. Microsoft was too busy servicing the cash cow (and fomenting internal politics) to allow any disruptions. They had already lost the next great battle the day the iPhone was released.
Google's Android only survived because they pulled the mother of all pivots the day of the iPhone announcement and immediately poured all their efforts into copying iOS. (Remember: Android started life as a Blackberry clone!) None of this is controversial - the original Android team members have confirmed it in multiple interviews over the years.
What Microsoft is doing now is extremely smart. They know they lost the mobile war and are moving on to the next battlefield: Cloud services. They're milking Windows on the desktop as they make the transition but it's just a smoke screen to buy time. Open sourcing technology, supporting Linux, etc are all moves designed to get them customers for Azure. They'll now happily sell you SQL Server for Linux licenses, or a subscription for Office on iPad.
As smartphones become more and more popular, they reach further and further down towards groups of people who can't afford iOS devices (unless you're counting second hand devices). I don't really see Apple's % of the market ever going up.
As the market matures and the hardware reaches "good enough" levels, the overwhelming majority of smartphones used will be the equivalent of the "beige boxes" of old (from the PC world). On top of that, the app competition is becoming so cutthroat that app prices will probably continue to go down (per app).
So, long story short: Apple will probably never enjoy a bigger share of the smartphone market than it did in the past and most of the competition will be around hardware and software with razor thin margins.
Meanwhile, more and more people from developing countries will start working in companies which use overwhelmingly... Windows desktops and associated software.
They will also use and pay for various services, some of which, as you noted, will be hosted on... Azure.
Microsoft's main cash cows will never dry up. Companies want/are willing/are able to pay for software.
I think that the longer term threat for Microsoft is Amazon, not Apple.
I see office software being commoditized instead. Then even the business guys can move off windows. If only google had some motivation improving docs. Maybe that hits another cultural wall. An engineering driven company can't produce tools for creating beautiful content.
There used to be specialists doing the graphs for various printed materials. Now it's all made by the marketers, consultants or number crunchers themselves. Of course the quality has been so bad ever since that happened, but nobody seems to care. Even designers don't really understand much about graphs.
Using iOS or Android on a tablet + keyboard isn't really the same experience as being able to use all the usual Windows applications if I want to, specially Visual Studio on the go.
However they are just pivoting like IBM did when they lost the PC market.
I never saw any trace of the success they appear to have in US.
https://en.wikipedia.org/wiki/Usage_share_of_operating_syste...