But what kind of complexity is that? And why would we conclude that AI has it while other incredibly complex systems (e.g. earth’s habitats, the universe itself) does not?
I’m far more open to the idea that many systems are conscious than the idea that this current generation of LLMs is somehow special.
I'd say that AI is too poorly understood at this point to conclude whether it does or does not possess some form of consciousness. It has a few features that privilege it over other systems like the ones you've described (though I think it's entirely possible that those too are conscious): the networks underpinning modern AI are largely inspired by those we've observed in brains, and the apparently intelligent behaviours exhibited by AI have historically only been exhibited by entities which we accept to be conscious.
I’m far more open to the idea that many systems are conscious than the idea that this current generation of LLMs is somehow special.