Qt is really quick and is used at plenty of places. Places where (critical) software is needed for internal use will be written mostly as native apps. For example monitoring and the like. And these places often use Qt.
I suggest you to try out the Telegram Desktop app (I think mac has a non-qt version as well so be aware). I really like using it for it’s speed as well.
My only gripe with qt is that one has to use C++ or python, other bindings are not