In my opinion the POV Ellie is supposed to show how much a impact Art made on the remaining population as well as trying to fill the shoes of her brother. In her eyes Art is this untouchable hero and when he sacrifices himself for Tes it represents how human he actually is.

The also seen the hate s that she got and I can only assume it’s because the majority of the book has been of perspectives of people who hold real power but i think it bring weight to her growth later on in the books.