I call it Star Wars because in 1977 when I saw it, that’s what it was. Throughout the 80’s that all anybody called it. I even remember thinking it was “wrong” and that it should be called “An New Hope”, but calling it that just felt weird. I only remember one person who called it A New Hope in the 80’s.
I don’t think people started calling it A New Hope regularly until after The Phantom Menace, and I think it happened then because the advertising put so much more emphasis on “Star Wars” than on “Phantom Menace” that people finally started thinking of “Star Wars” as the name of the series. Before that, if a person want to describe the whole series I think they said “Star Wars Saga”, after that they could just say “Star Wars” for the whole thing.
But for me, it’s too late to change. I may call it A New Hope sometimes for clarity, but I have to force myself to do it. If I just speak naturally, I’ll call it Star Wars every time.