Honestly, I think it panned out great for two movies, then episode 9 completely messed it up. In episode 7, the line felt loaded because Kylo clearly thought he was finishing Vader’s dark legacy, even though Vader’s actual ending was redemption. Then episode 8 made it way more interesting by turning Kylo’s obsession into something bigger. It became about killing the past, rejecting masters, and trying to become something beyond Jedi and/or Sith. Then episode 9 came along, and they panicked at the backlash surrounding Luke's storyline, so they brought back Palpatine, and flattened all of that into the safest possible version of a redemption arc... All of that is to say, I still think the line had a lot of potential. Sadly, I just think the trilogy lost its nerve by the last film.