^But, that’s not Luke’s arc in TLJ. That’s the moment it starts, but the overall journey isn’t about Luke overcoming his darkness. In fact, the arc itself is very specifically about why his failures aren’t a regression. I don’t know what to tell you.
I don’t know what to tell you, either. I saw Luke’s failure with Ben as a clear regression. Yoda supports that, saying “young Skywalker, still looking to the horizon.” This implies that Luke hasn’t evolved at all since the beginning of ESB, which seems like the definition of a regression.
When I say “needed to be told this way” I just mean that it’s clearly relevant. A logical next step to take from the OT that is more meaningful than Luke “finding the first Jedi temple” or something. This actually expands upon the themes introduced in those films. TROS is the film that rehashes.
Luke trying to kill Ben isn’t a “logical next step.” Like I said, there are a thousand ways TLJ could have expanded Luke’s character that wouldn’t feel like a regression. He could be tired of the endless cycle of war, and want the conflict to resolve itself. Or he could be scared of Snoke’s power, and worried that he wouldn’t be able to handle the situation. That would be a true evolution of Luke’s character. Instead, Rian chose to repeat a conflict that Luke has already faced.