[pjmlp]

Except that on iOS you can do everything in Objective-C/Swift if you feel like it.

Same applies to Android, UWP and even Tizen with their respective native languages.

So it is a conscious decision not to provide C++ APIs besides the old QtWidget and make developers use QML and its compiler instead, as far as I understand it.

[distances]

It's not as clear-cut as that. This is a case for automotive, and there isn't a single native UI widget set that Qt could use/mimic. It absolutely makes sense to use QML for custom UI development, it really shines there -- using Qt widgets for custom UI on touch screens would be madness.

I've used Qt myself for desktop, mobile, and embedded development. For mobile and embedded I would not use widgets, and probably not even for desktop. I understand why the widgets still has staunch fanbase, but they do not belong everywhere.