ESB, you have Luke fighting the man who killed his father (or so he believes), and in ROTJ you have a son fighting his own father.
However, it should also be pointed out that Luke did not interact with Vader at all in The Empire Strikes Back, nor did Vader have any particularly special relationship with Luke up to that point. The only thing Vader knew about Luke was that he was his son, but the two had no meaningful connection, and prior to that duel, Luke had never even spoken to him. Therefore, all the tension in that duel exists solely because you, the viewer, imagine what the two of them might be feeling in that moment. Which is essentially the same as imagining Anakin and Obi-Wan having more positive interactions off-screen compared to the ones that were actually shown in Attack of the Clones.
CGI lava effects
The lava was not created using CGI. Footage was taken from Mount Etna — a real volcano located in Sicily, Italy — and then composited into the background. The only CGI related to the lava involved the instances where it rains down just a few inches away from them. Otherwise, the scenes used real footage of Mount Etna. Furthermore, there are not many alternative ways to simulate such a scenario other than CGI and real imagery pasted in the background, as there are not exactly many practical effects capable of convincingly simulating lava, and it is not like you can start throwing real lava at the actors.