That’s an assumption, not an answer. And with a man as slippery as George Lucas - who makes “experimental films” in private that have so far never been publicly seen - it’s a fair question.
I always found that to be a bullshit excuse from Lucas. To me he has zero interest in “experimental films” and more interest in milking the same franchise too many times to count. He is a man with very limited scope who claims to be avant-garde when he is nothing more than a lucky idiot. He’s bitter because he couldn’t remake his beloved Flash Gordon and had to use his brain to make something original. Then he became even more resentful when smarter people could make better films than him, so he fired everyone who made the franchise great, and made four bad films that are still today black marks for Star wars fans. The only silver lining he got out of this is the merchandising, which was his true calling all along.