But I think George Lucas wanted to sell toys, and thus needed Storm Troopers and the Empire in the old trilogy.
Seriously, anyone who only complains about Disney marketing apparently is too young to remember the OT marketing.
I’m not talking about marketing that comes naturally out of a movie. But I do think they put the New Order and new Storm Troopers into the story to sell toys vs. it being needed or wanted in the progression of the story past ROTJ.
I mean look at the clone troopers in AOTC. That was there to serve the story i.e. Luke in ANH talking about Obi-Wan fighting in the Clone Wars.