Unless you lived through that time, you just have absolutely no bloody idea what a revolution Star Wars created. It was like nothing that came before and everything after it was never the same again.
I recall all the articles back then. I think Steranko‘s Mediascene had the definitive issue, even trumping Cinefantastique. The McQuarrie paintings were — to use the current term — just epic. And that so much of what he visualized actually made it into the movie was probably also unprecedented. I don’t think even Derek Meddings of Supermarionation fame had that degree of influence on a single production.
McQuarrie elevated design in film much the same way Apple’s Jon Ive today has shown the importance of design in technology. It’s not something that’s an afterthought, it’s there at the beginning.