Fiction on celluloid

There seems a trend in, say, the last ten years, to make movies where the “twist” is that some portion (frequently a large portion) of what you just watched, action committed to honest-to-goodness celluloid, properly dressed, acted, and scored, never actually happened in the story, that you have been watching the delusion of a main character filmed not as a delusion but as reality. I’m not going to list the films I’m thinking of here, because doing so will spoil the point of the movie, but I can name four five six without putting much thought into it. The questions are, how many can you name (again, please don’t list them)? And do you think this is losing its novelty?