I totally agree with you, the magic of star wars is largely a product of Lucas’s mind. Sometimes newer installments capture flickers of that magic, but it’s pretty sporadic these days, definitely not enough to build a foundation of nostalgia. Plus, there’s little to no philosophical message in the sequels, so their value rests entirely on the action and dialogue, which was kind of lackluster compared to the execution of the previous movies.
I totally agree about the EU, some of the finest pieces of Star Wars fiction are still not considered canon, and that kills me 😅. To put a point on my thought about Lucas’s contributions, while he didn’t write the finest of Star Wars, he did create the fertile soil it could grow in. It was his strange mixture of Taoism and science fiction that intrigues me so much, and I think it created a rich environment for storytelling and a very visually engaging struggle between the light and dark of humanity. Plus, he would actively draw in EU content that he liked, which is actually where the idea planet of Coruscant came from. Not only does Disney actively restrain and manage star wars third party storytelling, it also (generally) has drained the soil of it’s imaginative and creative inspiration. I can’t imagine much fiction being inspired by the characters and plots of the sequels, but I actually haven’t actually looked, maybe I’m wrong there.