Likewise, what reason do we have to assume that any given human is conscious?
A rock is outwardly pretty similar to me; in that it exists in the world, has obvious physical boundaries, and is affected by the passage of time. But it is not so outwardly similar that I assume consciousness.
An LLM is also outwardly similar to me, in that it can express itself in language, and seems to ‘contain’ notions about the world. But it is again not necessarily so similar to me, outwardly, that inward similarity is obvious (to me)
I find LLM frighteningly like many humans I meet: spouting "facts" that they have been taught. Like humans, when I ask an LLM to engage in critical thinking, the more advanced ones can.
Because sure, when we get knocked out, we're out. That's not an observation, it's a tautology. But there's nothing indicating that whatever remains doesn't have its own kind of consciousness.