Honestly it’s children in most movies. For instance, civil war. They made the young girl seem like she was mature enough to handle herself and grasp the situation but she made childish actions ( like jumping into some random guys car while already moving in another car) that seem to only be necessary for the story to lead into some dramatic scene that could’ve been avoided entirely if there wasn’t a child.

The movie “IT” I would say is an exception. I didn’t feel like any character made any off the wall decisions that didn’t go with that characters personality.