When George Lucas made Star Wars, the technology to produce the movie simply didnt exist, so he created it. Lucas worked with some extremely talented people and changed Hollywood in the process. I personally love the story of how he worked with Ralph McQuarrie, selling the idea of Star Wars to Fox executives. McQuarrie would create these spectacular paintings with huge scale and Lucas would tell him not to worry about how theyd produce it. Hed figure that out later.
He also worked with people like John Dykstra and Dennis Muren to build ILM from scratch to create the groundbreaking special effects that made Star Wars come to life. After ILM brought dinosaurs to life in Jurassic Park, he said to his friend Steven Spielberg, "I think we have the technology to make more Star Wars films", that is, films that used CGI on a scale that changed movies once again. Love CGI or hate it, filmmakers can now bring to the screen the exact vision they have in their heads, and it's all thanks to Lucas pushing the boundaries of filmmaking.