I agree with what you two have said. George Lucas’s work was organic, flowing from his mind with an overall logic and story animating what eventually appears on screen. It generally felt like things didn’t just conveniently happen. Locations didn’t feel like set pieces mimicking something we saw before in Star Wars. People used to complain about the 2nd Death Star - I don’t know if they do anymore - but that made perfect logical sense in the story and not as a mere callback or convenient plot device.

Relatedly, I think editing played a major role. For ANH especially, there was a messier work to start with that was carved into shape at the end. What was cut informed (or was even referenced in) other scenes which contributed to that bigger world feeling. I’m thinking particularly of Biggs and friends.

Part of my theory about the editing relates to the process employed in the prequels where Lucas was able to edit on the fly with digital tools. This informed subsequent shooting and at the end so much was baked in that it was harder to make edits to the story. Everything was connected and couldn’t be undone. Where cuts were made they could be oddly glaring, like Qui-Gon and Anakin running from Darth Maul. I agree with Stardust that TPM was nonetheless written with breathing room and we were with character on almost every parsec of their adventure. And it was still Lucas’s imagination at work for a coherent piece of work. I believe AOTC and ROTS suffered most for the changed production/editing process. The stuff that could be cut (mostly talking scenes) explained the motivations of the main characters.

A well-financed collaborative production of the biggest science fiction franchise, abiding by another grammar, as Stardust says, of modern filmmaking is a different beast.