I’ve heard the world-building argument before, and I question why go for the prequels in this regard when you can go for any other series with extensive world-building, and is executed better? Such as:
Blade Runner
The Lord of the Rings
Harry Potter
Game of Thrones
And many others. All of these, and the OT, are executed more competently than the PT, and are altogether more interesting. I just don’t buy that world-building argument.