QML already uses js?

If you want to use the same API of an existing web framework, I'm sure that wouldn't work, since QML is exposing C++ objects to js code, so the API is set.

But it's still an extra overhead that you need to first understand, instead of just writing a JS file with your code and then loading it.

> instead of just writing a JS file with your code and then loading it

If your js does no I/O at all, you can write pure js. But if you want to show some results, there is no way that you can do it without learning the relevant API to do that.

Every library is overhead that you need to first understand. There's no "just writing a JS file" or just writing a C++/C#/Java/Python/etc. file.

Maybe not implement React, but Qt would benefit from using something like Facebook’s Flux architecture, where state flows down from parent objects to children.

With Qt Widgets, it is annoying to create models (QAbstractItemModel), they are more difficult to implement than what it should and prone to errors. I haven’t done much QML beyond simple sample apps, but it seemed you still have to create Qt models for a lot of use cases.