Qt apps don't feel great on macOS, though it's by far the best for mac-ish UI. Dropbox was Qt for a long time and I'd argue it worked well for them. Its easy to fall into "uncanny valley".

On Linux, Qt apps feel a bit off in GNOME, though you can never satisfy everyone as its the wild west.

I think Qt also suffers from not really being anyone's favourite.

On the one hand, you have web developers who tend to not really appreciate the nuance of the desktop as a platform. They're not going to advocate for Qt, it's not CSS/HTML/JS.

On the other hand, you have native Mac developers who love Apple's toolkits (AppKit, maybe SwiftUI). They're not going to advocate for Qt either.

Lastly, you have native Windows developers who have been burned so many times they don't advocate for anything in life anymore.

I think Qt is only missing well-written, feature-complete bindings for a major JS runtime, including support for hot reload.

Developing UIs without hot reloading is too painful.

In my experience:

- Qt Widgets worked fine, but looked like a piece of software made in 2013;

- QML looks stylish and is a very nice language, but had a lot of weird bugs.

Neither of these are issues I'd run with if I were to make a web app.