Well, that wasn't said quite right. Yes, Kim can't be "saved" from the civil suit - but that's not going to happen anyway. She has nothing to take that would make it worth Cheryl's time.
Kim returns to the life she always wanted - helping people through the law. That had all been thrown away when she chose to chase the money with Saul and to destroy Howard in the process. She follows, before Jimmy does, the advice that Chuck gives, "If you don't like where you're heading, there's no shame in going back and changing your path."
Jimmy finally answers his own time travel/regret question when he decides that he'd rather serve 80+ years as Jimmy than 7 as Saul.
And he wanted Kim to know that he wouldn't have come to that conclusion without her.
Thanks. I like this. Its a good explanation.
First, I'll caveat again by saying I loved the show and even really liked the finale. But I had two quibbles:
1) They kind of played it both ways with Kim and Saul. Each of them was redeemed so they had a (sort of) happy ending. But at the same time, they didn't want to show these bad people getting away with everything so they are each punished also (civil suit v life in prison). That just seemed a little cute to me.
2) I find it hard to believe that (based on what we know about the characters) they would have the capacity to fundamentally change like that. Maybe Kim. But not Saul. At every turn for the last 11 years, he makes the wrong, self-destructive move. And now, when faced with the biggest decision of his life, he's going to all of a sudden be good? I just wasn't buying it.
In fairness, I have a negative view of human beings. So I just don't believe he would make such a complete change at that time.