@strypey
I'm not so sure about either of those arguments.
It's very obvious to most people when a mammal is suffering. With fish it's much less obvious, and insects even less - to the point that you can carry out experiments on insects without needing approval from an ethics committee. And attitudes have demonstrably changed over time.
In terms of the logic, you're arguing that if all members of a subset have a given property, then all members of the superset must also have that property. I don't know the name of the fallacy off the top of my head, but it's clearly a fallacy.
So far we haven't pinned down the neural correlates of consciousness, and there are cases where we can't even tell whether humans are conscious. So we've got a way to go before we can definitively rule out consciousness in a system that does a pretty decent impression of holding a conversation.
As I said, I think LLMs are almost certainly not conscious, but without actually knowing what process in the brain produces awareness, we can't say with 100% certainty that the kind of information processing LLMs do isn't it, and the grifters will be able to exploit that doubt.