Came here to comment on it being fascinating how xml has survived here and thrives on this front. Even in react syntax, in some sense. Natural fit?

As happy user of qt desktop framework, not sure in what sense it’s dated.

Not sure how qwt relates to this tho? https://qwt.sourceforge.io/

Making coherent ux with it still seems much easier than in qml, it has the right constraints and visual editing it is reasonably lightweight, unlike qml studio. Of course it has its flaws too but UX wise it is still hard to find an equally mature cross platform toolkit.