Did Adobe, Office 365 or Spotify have any real competitors when they went with this model ? Also, weren't they kind of so huge that they were almost monopolies, so they could do it and not fail.
Why this might fail is because of Steam, GOG, Uplay, Epic Store, etc
Windows 10 doesn't really have any competitors yet, and Microsoft is not dumb to miss the chance to push forward services, so even if future would mean no Windows, people still would be heavily addicted to software and cloud features of Microsoft,
it's no coincidence Microsoft finally buried Windows Phone and end is scheduled to December 2019 - they simply realized they can generate much more money just selling Office and OneDrive instead, and let users pick their platform (be it iOS or Android) and pretty much same could happen with gaming platform overall - they might actually push Store forward that much people might actually start using it, just not essentially under Windows or XBOX, that is future Microsoft has been planning