The overarching story George Lucas says is in 1-6 does not exist in the OT. The OT is way more like the first, second, and third movie in a three-part story than a fourth, fifth, and sixth in a six-part story, and ANH and ESB, the first two movies, are entirely filler in a supposed story about Anakin Skywalker. Hell, I can barely imagine the PT as taking place in the same universe as the OT. That’s not even a low the ST descends to.

The story of Star Wars begins in Episode 4 and ends in Episode 6. 1-3 are an entirely separate story that acts as a prequel to Star Wars. 7-9 are an entirely separate story that acts as a sequel to Star Wars.