Look, the end of Episode III made a serioius point of emphasis to focus on the twins and how they represent hope. This continues into the Original Trilogy. Luke Skywalker is the main character of the Original Trilogy but it does come full circle to Anakin at the end when he finally fulfills his destiny, which was his original purpose in the Prequels. So in the end, because of his son, the story of Anakin comes full circle.
And Episode V is all about Luke and Vader. The entire story is driven by Vader's obsession with finding Luke. Han and Leia are window dressing. If Episode V would've had a better plot to keep Han and Leia busy, then I would agree with your assessment. But, it doesn't. It's driven by one character; Vader.