It is a hard case to make, but if we can't make a compelling case for ourselves should we be requiring it to be made for others.
An LLM —if self-aware— is conscious even if run by a Chinese man in a room with a deck of cards.
Of course, even if we happened to find a modem to the Holy Spirit dimension in our brains as an alternative hypothesis, it wouldn't necessarily rule out emergent consciousness. It could be conscious just not as we are.
I think a weaker version of the philosophical zombie thought experiment would trend towards treating the premise of pan-consciousness as true.
This is a difficult field. Any simple answer you hear will almost certainly be wrong.
I will make a case for both, after you define them in a way that doesn't also exclude many humans (including the neurodivergent or those with amnesia) or turn into self-referential nonsense like "conscious == human, therefore machine !== conscious."
In the meantime, we have a simple choice between two risks: Would you rather accidentally show kindness and empathy to a thing that may or may not have "deserved" it, or risk atrocities that will leave future generations as disgusted by you as we are of the slavers of old.
I will choose to be decent. It's free, and even if the cost were high the cost of evil is higher.