I personally just dislike the idea that Kylo had to die to atone for his sins. He was a young man. Should he feel regret about his choices for the rest of his life? Absolutely. But he should channel that into doing positive things for the galaxy.
Vader was a completely different circumstance. Living in his body was a living hell, and he had already spent the other half of his life trying to be a good person as a Jedi. He was also old enough for his death to not be so tragic.
Yeah, while I bemoan Ben’s death a lot, at least it was Ben’s death and not Kylo’s. TROS would’ve been truly awful/irredeemable in my eyes if he hadn’t been redeemed to some degree lol. I’m like, hey, we got his redemption in a really good scene with Han, we got him absolutely fucking up the knights, we got the Reylo kiss! Did I want him to talk with Anakin? Of course. Should he have lived? Absolutely. Why didn’t he have a single line of dialogue (ow)? No clue. But it could’ve been way worse :S