I pointed something similar out on a related question several weeks ago - absent strong direction, LLM output regresses toward the mean.

The more banal your prompt is, the more banal the output is going to be. People have been testing LLMs with little things like “write a short fantasy story,” for years now and most of the stories are exactly what you’d expect: prosaic drivel.

I call this “generic in, generic out,” an LLM corollary to the classic GIGO (“garbage in, garbage out.”)

Of course one of the biggest problems we still see with LLMs is when you do the opposite. A highly detailed unique prompt is very likely to get terrible adherence or hallucination or both.