A content warning is a literary device. Specifically it is a form of foreshadowing. To add a content warning is to change the story the way adding or removing any other information changes the story.
In this sense, preference for content warnings is a preference for a *way* of storytelling. Content warnings mark out a genre of writing.
defending CW with actual reasons and examples, you might not agree with this
@nomi mind you that the most common content warning is literally a trigger warning. several people deal with trauma or other ways of reacting heavily and sometimes fatally to certain information. using trigger warnings can protect these people from avoiding these topics. a good CW doesn't describe what you want to talk about, but instead warns about the literary nuts, milk and eggs you might be allergic to. Just like epilepsy warnings for video materials. If a CW spoils the contents, it's not a good CW.
@nomi
Content Warnings are most clearly differentiated between varying societies- moreso geographic added into the mix.