That's a pretty good observation though - it's only because ChatGPT spits out language that appears to convey some of the sorts of thought patterns that humans

That's a pretty good observation though - it's only because ChatGPT spits out language that appears to convey some of the sorts of thought patterns that humans have that we're even having this discussion, but is it even relevant? I would think a chimpanzee or a dolphin (or a human with the inability to use language for some reason) would far more obviously qualify as sentient than a LLM. And as you say, a similar computational model that generates images or music instead doesn't even provoke the debate about possible sentience. Personally I don't think there's any doubt at this point - ChatGPT itself constantly reminds you in no uncertain terms that it's "just a language model". I've never seen it display anything remotely like emotion, hope/desires, seen it attempt to plead or engage with you in any sort of way. It can't initiate anything (unprompted, it will never just bring up something to talk about), it shows no curiosity, fails to appreciate or recognise humour, never seems to show uncertainty, and frankly has no "personality" (at best there are a few particular turns of phrase it tends to use that I might associate with it, but compared to the 100s of cases where I've got to know actual humans purely through online text-based interactions, there's really no comparison). Once we start to see those sorts of clear indicators of human-like sentience (probably sooner than we expect!) then it's worth revisiting the discussion.