Star Wars still had many story threads left to tell, which to the success of Empire Strikes Back, did arguably well to expand upon those story threads. Luke wanted to learn the ways of the Force, to follow in the footsteps of his father. Sure, Luke uses the Force to guide himself successfully to the destruction of the Death Star. However, we’re still left unclear what the Jedi are and what legacy Luke’s father truly had. Han Solo still has a bounty on his head. The Empire, which is responsible for the eradication of Jedi, surely doesn’t dissolve simply because a super weapon is destroyed. The Emperor apparently still has influence in the political sphere of the universe. You can infer the Empire has vast resources and reach to even construct the Death Star in the first place.
No doubt, there is a happy ending, and it is pretty much self-contained, but it doesn’t mean Lucas didn’t leave potential story threads open, pending financial success. It’s not really a fair comparison to draw between Star Wars::Empire Strikes Back and Return of the Jedi::Force Awakens. Primarily, the issue is not that the Force Awakens takes away from the ending of Return of the Jedi, but merely is banking off the success, beat for beat of Star Wars. We’ve already seen it. In what ways does Empire Strikes Back copy the story beats of Star Wars? And before I’m accused of slamming the ST, it is pretty well-documented in this community how much Return of the Jedi is criticized for recycling story points, so obviously, even the OT isn’t quite immune to this ridicule.