I think we need to start by asking a better question and not try to simplify too much. We also need to accept that some answers are complex and not everything can be reduced to a soundbite to be used to end internet discussions.
Let’s take a different question, like “what’s missing from a worm for it to be able to fly”. We might be drawn to the simple answer of “wings” but that isn’t quite right—ostriches and penguins have wings and they don’t fly, so obviously there are other variables at play.
How about “what’s missing from a spec of dust for it to be intelligent”. Well, there isn’t one thing missing and there’s no simple thing we can just add to make a spec of dust intelligent and sentient, its very nature needs to be radically different.
What test would you propose where an LLM (or an RL agent containing an LLM) would reliably fail, but where an average human would reliably succeed?