I had a HTC windows phone and it was not good in my experience. The app store was non-existent, the OS forced you into using its own social media experiences which were half implemented and janky vs. native apps, and the web browser was slow and clunky for the era (2010s). The home screen was enormously painful with all kinds of different sized icons strewn about and blinking, changing, etc. randomly--I could never find anything in the same place.

The only good thing I could say is that the settings were much simpler and easier to navigate than apple or android phones at the time. But that was really more because there was far less you could change or do in windows phones.

As far as effort put into it, Microsoft spent years pouring money and resources into trying to grow their phone platform. Remember they basically invented modern smartphones with Windows mobile phones--I was using 'real' web browsers on my windows mobile 5 phone as far back as 2006, years and years before the iPhone came out. They spent billions buying companies like Nokia, trying to get more developers on their platform, etc. There were at least two or three complete restarts to the whole platform. There were internal competitors even from the Xbox/game division (remember the Kin?). It just churned and churned and churned despite all resources and money thrown at it--all of it wasted in the end.