Windows Phone was so so good - it was THE phone I recommended to users who were on feature phones/non-smart phones because the UX was so simple and clean (and obvious) - with a side effect that if you HAD a smart phone before (Palm, Apple, Android, BlackBerry, the UX was contrary to what you were used to).
Windows Phone died because MS didnt do enough to build the app ecosystem, and bailed out too soon. I also feel webOS was a lost opportunity too - in some ways it was just too ambitious for the hardware of its time.
I really wish I had messed with Windows Phone when it was a thing. They were the only ones not to just ship a clone of an existing interface ASAP. But it was closed source and offered no advantages for carriers or device makers compared to Android.
WebOS needed WASM and a lot more to be successful. I think WASM/WASI is to the point that the next major platform build out can use it.
I loved the Windows Phone too.
I was one of two non-MSFT I knew of that had one.. and I bought it because an MSFT employee was showing it off and I was convinced. The concept of Tiles was great and Cortana was respectable. It felt comparable to Siri and way better than Google.
I used it for a couple years until the apps I needed started disappearing due to lack of updates.