I disagree with the argument for George Lucas. Lucas IS/WAS the source material. Some not liking what he did with it does not even come close to him not understanding the source material.
No movie is a solo endeavor- Lucas had lots and lots of help for the OT (Lawrence Kasdan, the editor whose name I forgot and the actors in particular)
We’re in sticky area about knowing material and being able to articulate it
I’ve known ballet divas and math geniuses who could do the thing but not explain the thing
And then there’s the example of someone like Francis Ford Coppola - who went from genius to pedestrian- I don’t think he forgot how to direct, he just had enough juice that he didn’t want to listen to the smaller voices that every creative really should listen to