^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.
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.