I said brain power isn't interesting because it doesn't prove anything. There are things that we absolutely know are not conscious yet have a lot of brain power, ie countless pieces of simple deterministic software that we can explain all the way down to the atoms like a sewing machine.
Yes other animals have demonstrated brain power that exceeds some humans, or even all humans while they are young enough, if you just go by some sort of puzzle-solving abilities. The fact that you can figure out how to unscrew a jar lid, and so can an octopus, doesn't imply anything about the octopus being the same as a human in an octopus body.
Similarly observing something simpler exhibit some of the same outward behaviors you and every other human does also doesn't mean anything. Humans do a lot of very simple things. A human seeks food and comfort and avoids pain and damage. And so does a plant. Electric motors turn shafts, and so do humans. So you have to discount anything that's merely a commonality like that, including other things that seem more complex, and so seem like they are what makes us different. We do also have more simple brain power than most animals, and so it is like a correlation with consciousness, but it is not consciousness itself or automatic proof of it and doesn't automatically or necessarily produce it. It's probably a required ingredient though. IE all beef is meat but not all meat is beef, all consciousness may have brain power but not all brain power has consciousness.
But, repeating an example I used in another comment, if you had no other interface with the world except a remote controlled roomba, you would be able to make yourself known. Not by anything as plain as writing out words on the floor, but by actions. There are an infinite number of ways that you a conscious being could disclose your existense to me who can only see the roomba. You could be anything from caring to menacing by simple actions. Because it's not the capacity to roll across the floor, it's where & when you choose to roll across the floor that ends up speaking and disclosing intent, which discloses the "you" in there.
Watch any horror movie about the robots going wrong, or like twighlight zone episodes where you don't actually see much action but the person wakes up and there is a knife sitting next to them, and the presumption is the creepy doll placed it there while they slept. It's a message that they could have killed them any time they wanted to, and they want you to fear.
No other animal has ever done anything like that, that can only be explained by "I want you to know that I know." or more generally "I want you to have a particular thought.", only things that can be explained much more simply and directly. Some things seem to come close like animals caring for other animals, bringing another animal food etc, but that is really just anthropomorphizing, because we also have all those same animal condition components to our own existense. We also feel hunger, feel a desire to relieve someone else's hunger, protect our young, etc. And animals do have some ability to model what they see. They can observe another animal and model what it wants or fears etc, because the ability to predict other things behavior is very beneficial to survival. And we see that and think it proves more than it does.
If you're a roomba that pushes a cookie across the floor to me, that doesn't prove anything all by itself, but it could be part of it. It's like how a word isn't a novel or a philosophical concept, but the philosophical concept is communicated with words.
The idea is to try to recognize how llms are like a misdirection tricking us into thinking certain things simply because they use text as the thing they manipulate. That makes them seem way more human than they really are, simply because they are slicing and dicing prior recorded human communication, which up until now has been something unique to humans. You don't need any words at all to make yourself known to me as being not just a roomba.