Well, in theory you can write narratives without character development. A great example of a media with little character development is The Road (talking the film). The Father in that film doesn't change very much, even when provided with opposition from the Son, because the world is so brutal that he cannot.
I think that the most important thing to discuss when thinking about the necessity of character development is considering your characters to be real people. Lay out who they are and what they believe in before getting too far in. Then, as the narrative progresses, you have to enter the shoes of those characters and ask yourself; "Does this challenge my beliefs/actions?" If whatever they encounter could change their perspective, you should address it and allow for it to change the character's view on the world and how they act in the future. If you are very careful about it, you can write a narrative where characters aren't necessarily forced into changing their beliefs or opinions.
A lot of the problems related to this is sidestepping character development when it should be necessary. Whenever a character follows their heart and acts in line with what they believe, there should often be consequences. When Dimitri finds out who was responsible for the death of his parents, when Chrom fails to prevent tragedy, when Corrin is forced to fight against his family, all of these events are profound and should trigger a shift in the way the characters act or think. The main reason for this change being demanded is that trauma changes people, and the point of fiction is in part to convince readers that imaginary people are real people. Thus, if a character experiences trauma, they should respond in some way, especially if they are at fault in their own perspective. The complaint of lacking character development comes into play most often when characters should experience trauma and should change their ways, but shrug off opposition and let the story continue without addressing their personal conflict.
In summary: As long as a character reacts normally to crisis, trauma, and consequences, they don't need to develop. Although, crisis, trauma, and consequences tend to change people under normal circumstances.