I generally agree with the OP except that lumping QML into the old-school GUI techniques isn't a proper fit. Traditional Qt Widgets, yes, but QML is indeed not far from the React-style of GUI programming.
No you're still quite wrong. QWidgets-based UIs still consist of a DOM driven by a state machine that handles events. UI files have a 1:1 correspondence with components and state machines still control changes to the widget/DOM tree.
