Whenever there's a female lead in a film or a TV show, they are usually accompanied by a love interest. And depending on the story, despite some bumps in the road, that female character usually ends up with someone. Unexpectedly, Barbie ignores those rules by not having Barbie (Margot Robbie) get together with Ken (Ryan Gosling). And it works.
Source:https://www.cbr.com/barbie-proves-love-interests-no-longer-essential/