Here are a few advantages of an Windows Operating system:-
Compared to widgets and icons in Android and iOS respectively, Windows has "Live Tiles" which are way better in functionality and customization options.
The new presentation from Windows is at par with Google Now.
Ability to sync seamlessly with your PC and phone.
4. MS Apps:-
The microsoft products like office documents and Outlook work nicely than on non Microsoft OS.
5. One Drive:-
A great cloud storage has a lot to offer in comparison to Google Drive.
On the security front, Windows OS is comparable to iOS. All apps are reviewed and approved by Microsoft.