Susan Blackmore observed that you can implement all the known functionality of human consciousness by answering the question 'Are you conscious?' with 'yes'.
We don't have any broad agreement that it does anything else, and we know that we do lots of things unconsciously despite our commonplace beliefs to the contrary.
Blackmore's argument is that people say they are conscious when they are awake and you ask them, but that's its only known function. Your reply appears to assume this is wrong. Do you have an argument to support it?
Interesting, so someone who has never said those words has therefore never been conscious, and we can treat them as we treat anything lacking consciousness. Hooray, we just solved all human problems: if someone has a problem, just turn them into soylent green! But only if they don't say those words!
> so someone who has never said those words has therefore never been conscious
That is not the argument.
People may well be conscious (no matter what they've said). What is the function of consciousness? Intriguingly, upon some reflection, we know of nothing that could not be done without consciousness [1]. One can seek food, mate, avoid danger, and so on without consciousness. One can speak and be intelligent without consciousness. So, why did evolution endow us with consciousness? Big puzzle.
[1] And now for the footnote/joke (which illustrates the profound point made in the paragraph above): The only thing we know of that one cannot do without consciousness is this: to truthfully answer "yes" to the question "are you conscious?".
Upon almost no reflection, you could make a long list of things that cannot be done without consciousness, or at least cannot be done yet and we have no good reason to believe could ever be done without consciousness. Can you understand anything without consciousness? Can you have an identity without consciousness? The argument you're presenting is that if physical mimicry is close enough to the original then it is the same thing, if we just assume that consciousness is nothing. It's saying that Frankenstein's experiment was largely a success.
Susan Blackmore observed that you can implement all the known functionality of human consciousness by answering the question 'Are you conscious?' with 'yes'.
We don't have any broad agreement that it does anything else, and we know that we do lots of things unconsciously despite our commonplace beliefs to the contrary.