@Grey Wolf
I'll note here that you've mentioned previously you haven't read output from current-generation LLMs.
I don't know where you got that from.
I haven't used the latest LLMs but I wouldn't be surprised if some SOL authors had. Unfortunately, many don't even acknowledge their use of AI, let alone what brand and version.
Meanwhile, both J. K. Rowling and a number of SoL human authors use more em-dashes per unit of text than any LLM has ever used
That seems like a claim plucked out of thin air, unless you've checked all the outputs from all the LLMs. And given the recent tendency for LLM nationalism, I'm sure you haven't.
JKR's published stories use lots of em-dashes in dialogue (being a Brit, they may actually be converted dashes), and her characters have lots and lots of dialogue. Her usage is specific and correct, unlike the scattergun usage by many LLMs. That's another reason to treat your claim with scepticism.
'Depth' is contingent on how the LLM is used. If it's used well', there should be 'depth' - that's inherent in using it well.
LLMs simply haven't the capability for depth. That probably requires sentience. No matter how well anyone uses a tool, it can't produce something it hasn't been built/trained to do.
LLM output from poor prompting and lazy use will almost certainly have tells, and that's most of what we see. But that just says that, when not 'used well,' they will produce bad writing.
According to that, every usage of an LLM involved poor prompting and lazy use. Although I don't necessarily accept that an AI tell is a sign of bad writing. After all, many of the authors whose works were stolen to train the AIs were pretty decent, so the original use can hardly be described as bad writing.
AJ