Windows revenue has been shrinking for a few years now. The growth is in Azure and related cloud technologies. Sure Windows probably won't ever go away (until

Windows revenue has been shrinking for a few years now. The growth is in Azure and related cloud technologies. Sure Windows probably won't ever go away (until a massive paradigm shift as you mention) but businesses are not upgrading like they once were. You have a mixture of reasons for this, BYOD has chipped away at some of it and forced companies to allow non-Microsoft (i.e. Apple) systems to connect to the network for remote and onsite. With more and more work being done in the browser it makes specialised software that forces upgrades to Windows out of the picture. I have worked for a number of large companies and recently the reduction of annual spend on Windows clients is pretty staggering. With almost all "managers" going BYOD with their (mostly) MacBook Pro's and onsite machines lasting a good few years longer than they used to it means we just don't need to buy as much from Microsoft. You can see Microsoft know whats up as well. Windows Enterprise subscriptions and Azure are the future for Windows in business. For home users Windows is already "dead" from a revenue perspective with the exception of charging via the OEM at first sale. Android, macOS, iOS, tvOS, all the operating systems home users are aware of are free upgrades on supported devices. This is where Microsoft has a problem as obviously they support everything so they can't lock out some users with a "2011 Dell XPS". However going forward I expect we will see them do something along these lines with limitations around what minimum hardware is supported so you will only get upgraded to the latest Windows if you have AVX2 or such based hardware.