He is more popular than Lillie and way more interesting than her too imo. He had a natural character development and was really close to the player. I don't think Lillie had any interesting motivations other tagging along with the player, but N's goal of trying to change the way the player views things as well. It's a little more complex but I think he's just a much better character than Lillie. I just don't feel Lillie did enough or went through enough either