> because those libraries provide you with so much more functionality than just the UI.

Comparing GPUI to Qt based only on what they offer gui-wise is fair, in my opinion. What QtCore provides is sugar over C++: the object model, the signal system, some data types, many helpers. But the thing is, all of those things are in Rust already. They're even in modern C++.

So comparing a Qt hello world that uses QtCore+QtGUI+(QtQML|QtWidget) to a Rust GPUI hello world seems fair to me. It's not like the author also counted QtNetwork, QtSQL, QtSVG, QtHTML, etc.