Dead narrators aren’t much fun
Once upon a time, not so very long ago, there was a very popular movie that had a surprise twist ending in which it was revealed that the protagonist was actually dead. (Because I'm giving away the ending, I'm not saying the name of the movie, just in case anyone hasn't seen it.)
The idea of a surprise twist ending (or STE) in which it turns out the protagonist is actually dead was not a new one. It wasn't quite as common as "And then he woke up!", but it wasn't exactly unheard-of either.
But anyone who hadn't heard of it before the very popular movie quite likely heard of it after that movie.
My point being that by now, it's extremely difficult to pull off that STE in a new story, because most readers will have encountered the idea before, and so they'll see the hints that the author drops in the early part of the story, and they'll think "I bet the protagonist is actually dead." So when the surprise is revealed at the end, it's not a surprise. Which makes the whole story seem flat and pointless.
As you know, reader, I'm not fond of STEs. I would be just as happy if we never received another STE story.
But failing that, I would at least prefer that authors not write STEs that are so common and widely known that they won't surprise most readers. Which is to say, if you're going to have an STE, at least come up with one that wasn't the STE of a very popular recent movie.
(Written back in February but never posted for some reason.)