Star Wars, in particular, seems to have such good editing (which it genuinely does) because of its tight, quite linear, story construction. The sequels, being more all over the map by necessity, and often being episodic rather than linear ... suffer from seeming to be less well edited. But is it the editing or the story construction?
Individual sequences may be well edited, shot to shot, in any of the O.T. films. But there's also the matter of how a film is edited together as a whole ... and that's where intangibles like the story, script, principle photography, etc. get jumbled together with the editing to make it difficult to separate out the skills.