> That’s called “interface builder” and it falls short at edge (or just non-trivial) cases in all frameworks ever created. Qt, gtk, whatever-tk, any windows, mac, phone ui.

That's interesting, I've used those a fair amount of time generally with success for e.g. config UIs, etc.

e.g. look at the amount of Qt-based UI dialog merely on github : https://github.com/search?q=extension%3Aui+language%3AXML+QD...