There’s probably a business lesson in there somewhere about how your biggest customer can become synonymous with your actual product, and you get ruined by association.
QML remains to this day superior framework to native Android UI development. Only Jetpack Compose, and SwiftUI on iOS, are starting to come on par with what Nokia had with Qt/QML over a decade ago.
Nokia actually had all the right pieces (Qt, Maemo/MeeGo, Symbian for feature phones, unparalleled engineering and manufacturing talent) for continuing their world domination, but their management was just laughably bad. It was all lost to in-fighting between teams and an inefficient middle manager heavy corporate culture it seems.
And years later they are still terrible. At least Android looks like an interface designed by people who have never seen GUIs before: GUI elements (warning) obscuring other GUI elements with no possibility to move them.
"Hey let's take GTK3 with all it's problems and love for empty space and put that on a phone..."
I missed that phone when it died, but Android on the Dell Streak was great step onwards for me.
The Symbian UI was extremely clunky. I am not sure it even had touch screen. They had whole keyboard, but you had to navigate menus with arrow keys. Why not give user the full power of the keyboard, like Emacs or Vim? Why can't I have menu options on hotkeys?
I think people forgot about how bad phone UIs were before Steve Jobs' heavy focus on UI. And I am no fan of touch-based controls, still want a proper keyboard.