C++32’s std::ui will solve that.

Sure, but Qt (at least QtWidgets) is still really good, even if it is aging quite badly at this point.

The signal/slot system actually doesn't need MOC anymore, and the custom container classes are pretty obvious.

That said I think some Rust GUI frameworks are finally starting to mature. I quite like gpui-kit (formerly gpui-component). Maybe not as easy to use as Qt but it doesn't matter so much now with AI.