That was Rey being the new Luke, being the only one who thought Kylo could be redeemed.
Like Luke was the only one who believed Anakin could return from the darkside.
Rey was right by the way they won the war because Ben Solo was redeemed. He saved her from dying and traded his own life.
I guess you could complain they just recycled episodes IV-VI and the Disney movies offered nothing new.
Ben turning to the light restored the Balance.
Except Rey has only known Kylo for a few days. Vader was Luke’s father, and Luke knew Vader had once been that great Jedi and friend Obi-Wan told him about. Rey and Kylo have basically only just met, and the fact that her feelings toward him go from seething hatred to seemingly having feelings for him to the point that she’s willing to basically ship herself in a box to the First Order flagship to try to redeem some awful man she recently met is stretching my belief.
Simply, Rey is not Luke, despite the films treating her like she is, and I honestly think it’s a reductive treatment of her character. She has a different personality, different goals, and different relationships. Given the circumstances, Luke’s behavior towards Vader in RotJ is believable. Rey’s behavior towards Kylo is not.
Also, the fact that Luke saw no hope for redemption in his nephew, despite Kylo being much more openly conflicted than Vader, is not something I can believe. Neither is Luke trolling his nephew and deliberately trying to get a rise out of him rather than earnestly trying to talk him down.
I should stop.