There's also the problem that to lay people, LLMs are sufficiently advanced as to be indistinguishable from magic. I suspect that colours many of these responses.
It's obvious a LLM can do anything a computer can do.
As an answer to "Why would LLMs exhibit sentience?"
It is because that would mean that no algorithm could exhibit sentience, claiming that would require some causal action that cannot be performed by an algorithm to create sentience. Some people like to point to quantum effects, but that would require the cause of sentience to be pure randomness. That seems even less plausible. Absent of any evidence that human brains are doing something that no algorithm could do, it would be reasonable to assume that sentience could be algorithmically obtained.
We've had computers that can do anything computers can do for as long as we've had computers.
I was addressing the argument that something is not sentient because it is a LLM. That requires all LLMs to be non-sentient, and by extension, since LLMs can do all algorithims, all algorithms must not be sentient.