Because the whole premise is Sumire adapting to an entirely different world with Fikar. Especially in the last chapter, you can see her loneliness, desperation to survive, and her missing her family being healed by the presence of good people and Fikar. This is a healing story
So like, why did she have to Be a transmigrator ? It did nothing for the story besides giving it its “isekai” tag (⊙…⊙ )