But since Microsoft were 2-3 years late, there were not many apps. And then they shot themselves and all people who already bought a Windows Phone device in the foot, by completely forking the ecosystem with Windows Phone 8. Leaving early adopters stranded on Windows Phone 7 and no ability to run newer Windows Phone 8 apps.
and had no apps. Windows Phone/Mobile had atrocious developer share. There few apps that were available were of terrible quality. Ironic, considering this happened in the era of a sweaty Balmer screaming "Developers! Developers! Developers! Developers! Developers!"[1]
It took Android 10 years, for something like AGK to come up, and even then it is a mess of development experience.
Used all Windows Phone versions, and they all got more updates than most my Android devices.
Their market was around 10% in Europe when they decided to give up.
Nokia went for Windows because of the acquisition target, not because of quality of the OS. With that, they prioritized business strategy over product quality, and we all know what happened after.