By what standard?
Xcode is historically inferior when compared to the likes of Jetbrains IDEs and Visual Studio.
And their documentation is so bad devs resort to watching WWDC videos in search for scraps of information.
Anecdotal stories of developers watching WWDC videos for info means something? There are millions upon millions of developers who worked and created apps just fine without referring to WWDC videos.
Maybe because xcode has been the only sensible choice since forever due to apple's imposed limitations?
That's like saying webkit is the best browser engine since it's the most used one on iPhones.
This line of reasoning, if one can call it that, is laughable.