It sounds like he meant that from a visual standpoint in particular.
EDIT: Also wanted to say that I’m really enjoying how we’re having an interesting discussion about this even though we have different opinions!
Well considering Lucas stated the following about his plans for the ST, I suspect this opinion isn’t just restricted to the visuals, even though that quote seems to focus on that aspect of the film:
GL: [The next three Star Wars films] were going to get into a microbiotic world. But there’s this world of creatures that operate differently than we do. I call them the Whills. And the Whills are the ones who actually control the universe. They feed off the Force.
GL: If I’d held onto the company I could have done it, and then it would have been done. Of course, a lot of the fans would have hated it, just like they did Phantom Menace and everything, but at least the whole story from beginning to end would be told.
Lucas thus clearly feels the whole story as he outlined it to Disney during the sale has not (yet) been told, and while I suspect certain elements of his outline ended up in the final product, he obviously had something very different in mind for the core narrative. That’s not to say his movies would have been better, but they would definitely be more original, and expanded the universe and the lore to a greater degree.
Iv’e read what GL had planned for an ST and I’m sure as hell glad he didn’t.