Just had to comment and say that I agree 100% with this take. Even if you don’t like Abby, you’re going through the stages of grief alongside Ellie, and in a way, playing as Abby allows for an easier transition into the acceptance stage, and makes forgiving her easier in the end. But, even if you don’t forgive Abby, you have to at least recognize that killing her would destroy Ellie. Just like how as player we have reached a stage where we have at least accepted Abby, and understood that killing her would destroy Ellie, Ellie herself also has to accept this reality and let go. In short, playing as Abby allows us to reach that acceptance stage faster than Ellie, which is what makes the epilogue even more heartbreaking - we may have already let go, but Ellie hasn’t.