Interesting. A lot of open source software uses it via the python bindings. What do you mean by feels? Slow? Look? Layout? Isn't it all os-native widgets?
On mobile I don’t believe it uses native widgets. I think the official Qt Company demos are done with Qt Quick. They just look off, the rendering of the controls isn’t quite right and some of them don’t handle screen rotation well.
It’s been a while since I’ve tried them though, maybe it’s improved but about a year or 2 ago I wasn’t impressed.