I’d say Rey’s arc had climaxed pretty well in TLJ at the time of viewing. Her rejection of Kylo in the throne room is when she decides that she’s going to be a Jedi, no matter what Luke or Kylo say or who her parents were. It’s only in retrospect now that her story was “incomplete” then, with TROS saying “nah, she’s still not over her parents and still doesn’t feel worthy of being a Jedi, even though TLJ showed her successfully overcoming both of those personal challenges.”

You could argue it goes even further back than that. In TFA, Rey taking the saber and fighting Kylo is where she accepts her destiny with the Jedi and Maz’s words that her future is ahead of her, not back with her parents on Jakku. It was only after that in TLJ that they say “well maybe she only agreed to bring Luke back, not become the hero herself, and she’s still concerned about her parents and external validation even if she’s not going back to Jakku just yet.”

Rey basically has the same arc in each of the three movies, just going a bit more into the details each time. Obviously now that internal story ends with TROS, but which of the three climaxes was most satisfying at the time of each movie’s release is up to the viewer, as 8/9 could have just as easily said “that part of Rey’s internal conflict is over now, here’s a new challenge for her.”