Honestly I never really liked the idea that someone as evil as Vader could be saved. If Luke had succeeded right away and he and Vader took out the Emperor…what then? Vader doesn’t pay for any of his crimes? Because if he is going to pay for his crimes, he’s either going to be executed or spend all the galactic years of his life in prison. And if he’s not, well then what?
Same thing with Ben at this point. It’s too late.
Being saved is different from punishment and forgiveness. I think there are people who commit evil acts who do change. Whether they stay behind bars is another matter. I know someone who refused to forgive a parent for something they did (vis a vis others) and even refused to attend the parent’s funeral. I think the child was wrong but that’s me.