I had the Lumia 1020 and it was a great phone. Windows Phone seemed to be gaining momentum around the 8.1 days, I think it even reached double digit marketshare in Europe.
Then it felt like Microsoft just dropped the ball, almost on purpose. New phone models slowed to a crawl. You couldn’t just go buy the phone you wanted at the carrier you wanted like you could with an iPhone. Instead, it was a mess of exclusives and I think Sprint just didn’t get anything except the basic low end stuff.
On top of that, there was no true flagship for a while.
Windows Phone was more flexible than iOS, and more performant and “cleaner” than Android at the time. But then the OS stagnated and Windows Phone 10 couldn’t make an impact and wasn’t fully baked.