Say we agree that a lot of things outside of humans are sentient. So what? Humans are sentient by that doesn't prevent treating them with with wars, bombs and what not. In fact trillions are spent every year on weaponry aimed squarely at the most sentient of all sentient beings.
Why would anyone worry about LLM's welfare when there's no peace movement to speak of, wars are raging as if they're normal, but hey, look the LLM is crying?
Let's fix human welfare first, then we can sit down and have a really long conversation about the feeble emotions of token generators.