The Smurfs go to the real world for the same reason they do everything else in the movie, which at different points invokes the multiverse, serves up bewildering lore, and includes a pillar-of-light showdown out of a superhero movie - because no one involved in it has any idea what they're doing.
The use of music in Kyle's short is particularly hilarious - stock, YouTuber-esque music underpins every sad moment with jarringly upbeat vibes, creating a juxtaposition that delivers laughs as well as discomfort.
I just think that it's lazy on the part of the studio. When Universal Pictures president Peter Cramer told him the studio was planning a remake, he asked to direct it not out of enthusiasm, but out of concern over how another director might interfere with the version of the story he and Sanders put on screen.
Elio is remembered as one of the big box office flops of 2025 despite being beloved by viewers and visually beautiful, resulting in the worst performance in Pixar's history.