a common consensus on chapter 2’s evil route seems to be that (spoilers) getting noelle to kill your enemies for you is a way of getting around the “your choices don’t matter” rule… but at risk of sounding like a pedant, isn’t the choice to manipulate someone else… still a choice you’re making? and perhaps more importantly, “your choices don’t matter… but other people’s choices do matter” would be a bizarre moral position for a game to take.
i think it may be more helpful to view Deltarune in terms of what is “real” and what is just “acting”. choosing to kill a chess piece doesn’t “matter” because a chess piece is an object. the very nature of the darkners is as NPCs; their “purpose” is to assist lightners and nothing more. the dark fountains cause these objects to take on more meaningful forms, because some objects can have profound meaning to the people they belong to; but at the end of the day, destroying an object is just destroying an object.
but Noelle isn’t an object; she’s not from the world of fiction and “acting”, she’s from the “real world”. causing mental anguish to Noelle has real consequences in Kris’ day to day life, at school, around town… and it seems to have been established early on that “your choices don’t matter” doesn’t apply in the world of light. the real world has ongoing arcs that you play a part in; you can choose whether or not to help Alphys and Undyne connect with each other, and whether or not you decide to become friends with Onionsan in chapter 1 carries over to chapter 2.
perhaps the reason chapter 1 doesn’t have an equivalent evil route is because those toys belong to Kris - it wouldn’t be out of the question for Toriel to have raised her young child in the school at which she is employed - or are long abandoned and don’t really belong to anybody. but the cyber world is Noelle’s world. being connected to technology and the internet is important to her, personally. while destroying objects may be generally a morally neutral act, destroying something that has sentimental value to another person can have a real impact on that person.