I believe the point is that Star Wars is inspired by enough things and puts enough creativity into the combination that it isn't an obvious rip-off of any of its inspirations.
Everything has inspirations. Truly new ideas are rare and often the first author to a truly new idea doesn't necessarily do a great job with it, and certainly can't explore it fully in any one work. But there's definitely a category of "direct ripoffs with little more than the proper nouns filed off". I'm not even targeting that at the current discussion; it has been observed by many people that rather a large number of "Hallmark movies" are literally just the same story, beat for beat, with the details of the participants in the love triangle slightly altered and recast. There's entire genres that are arguably just ripoffs of the genre template, over and over.
I always heard that George Lucas was inspired by The Hidden Fortress by Akira Kurosawa. If you watch it (and it's a great film) the parallels are quite obvious.
Eh this is more of a stretch, George was more inspired by The Hero With a Thousand Faces than he was Dune. Star Wars is telling a completely different story with a different central idea than Dune. The only obvious similarity is a desert planet.
