Not OP, but QML is not a great language to put more logic than simple bindings and functions like

    Button {
        text: "Save"
        enabled: textField.text.length > 0 // this is reactive to the value of a TextField
        onClicked: Backend.save()
    }

as soon as you try to for example implement the save method in JS/QML this starts to become very painful as it often ends up with a lot of spaghetti code. The very cool thing with QML is that the save function can be simply implemented in C++ like this.

    Backend::save()
    {
        // call QFile/QNetworkRequest/...
    }

It force the programmer to split their logic from the UI layer which I don't consider a bad thing.