I remember that quite differently. Windows Phone 7 lacked many basic functions like Bluetooth file transfer, the audio player didn't support gapless playback, alarm clock could not turn on your phone (a staple Nokia feature), Internet Explorer was always behind in supporting web standards (and Microsoft did not allow other browser engines). WP7 didn't even support front cameras until Mango Update.

The snappiness of apps was also hindered by network I/O in the UI thread (I mean wtf Microsoft).

WP8 did some things better but it was too little, too late. Nokia at some point bitterly complained about Microsoft's inertia in getting important features implemented that Nokia needed in order to sell phones (besides the apps, but that is another whole can of worms). https://www.techspot.com/news/53405-microsofts-slow-developm...