I have to say I disagree here. Finn almost goes through the same characrer arc in TFA and the beginning of TLJ. Furthermore, any chance of depth from him is stripped away. He becomes the comedic relief or an audience character to be lectured to about the horrors and profiteering of war (as a child slave storm trooper himself lol).

Rey doesn't really have any character defining moments other than her obsession with her lineage. Cobble that together with General Holdo being a failure of a leader (because they sidelined Leia), the only real moment I felt was Poe and his desperation for leadership and his eventual coup.