Why buy any character sequel or DLC - you know what's going to happen. Sometimes it's about the journey not the destination, or even *shock horror* people want more TLoU because they enjoyed the main game.
Why, because it has cutscenes? There's great gameplay there, 15 hours of it versus 2 of cutscenes actually. But I'm not going to get into that again. Don't play it, nobody gives a damn.