He then started digital capture and exhibition in the prequel SW trilogy, changing the industry.
He also built his own studio (Lucasfilm) which was the dream of all the 1970s New Hollywood filmmakers. He did it by himself, on the basis of pretty much original IP.
George Lucas is absolutely a visionary.
With all due respect with Lucas filming technology and endeavours.
As for directing, evidently he did approach a few directors initially. They all said he should do it himself. After his picks turned him down, he surely didn't want to let just anybody direct it, so maybe that's why he decided to do it. From wikipedia:
In November 2015, Ron Howard confirmed that he, Robert Zemeckis, and Steven Spielberg were approached by Lucas to direct The Phantom Menace. All three approached directors told Lucas that he should direct the film, as they each found the project "too daunting."[33]
This, coming from the guy who fought against enormous odds, at great personal cost, and spent every dollar he had to get Star Wars made.
That said, after reading Droidmaker I got a renewed appreciation for all of the different things Lucas not only had the vision for, but did, and did well, even though Lucasfilm/Lucasarts was running in several different directions at once. I can't think of any other filmmaker who invested so much of his own $$$ (SW profits) into essentially movie technology R&D. Maybe Kubrick comes close, but Lucas spent enormous amounts of money doing R&D to build the tools/tech/workflow that the movie industry relies upon today.
Lucas deserves some sort of "lifetime achievement award" for his contributions to the medium.