Why did they stop using the secretary will disavow your actions on Mission Impossible?

In "Mission: Impossible," the phrase "the secretary will disavow any knowledge of your actions" was used to establish the covert nature of the missions and the agency’s deniability. Over time, the series evolved to focus more on character development, complex plots, and global stakes, making the line feel less relevant. Additionally, the shift allowed for more dramatic storytelling without the constraints of constantly reminding the audience of the agency's disavowal. This change reflects a broader trend in action films towards deeper narratives and character arcs.