Is character change necessary?

There's a lot of advice that says character change is part of good story telling. If the character hasn't changed/grown, then the events of the story aren't, well, story-worthy. But I've read good stories where the events occurred only over several days to a couple of weeks at most. Yes, the events were nail-biters, but the protagonist's basic personality - their sense of right and wrong, and their values - didn't change with it. At the end of the story, they have a sense of accomplishment that they overcame their obstacles the story was about. The outcome of their situation changed, but their personality didn't.

So, why does everyone say character change is necessary?