Absolutely no one ever has been shown to be more productive because they don’t use GUIs. It’s kind of preposterous to think that could be true.
Anyway, my point stands. "Absolutely no one" without any context makes no sense whatsoever. There are a number of tasks that are much, much more efficient to perform in the terminal than in a graphical interface. So no, I didn't misunderstand your point - you're just wrong.
> any cases where a GUI is definitely better
Sure I can. Not all of them are though. So be careful with exaggerations.