Whilst I agree with the simple fact LLMs are in no way sentient, sapient or anything of the sort, I disagree with his argument. His argument boils down to: I can create this small part of a greater whole in a game, anything in the game isn't sentient therefor the whole thing cannot be sentient.
But when we assume a human is sentient and look at the basic building blocks of our brains, the same equivalence can be made. Let's say for our brains to do the brain thing all it needs is neurons (reality is much more complex, but for the sake of argument). I think nobody would argue the neuron itself is the bit that is sentient. And we even have a whole bunch of neurons working very similar to how they work in our brains together in small animals, we don't consider them sentient. We can even simulate the neurons working together in a computer (even in AoE2 if it's Turing complete) and we don't consider the computer or any of the parts sentient. So what's the difference?
I feel the difference is both scale and complexity. It isn't the parts of our brain that are sentient, it's the whole thing. And I'd even go further and say the brain as an abstract isn't enough, it has to be a brain that has been filled with memories, experience, input and output. Then the whole is considered sentient. It isn't the matter itself, it's the actual processes that we consider to be sentient.
When one would simulate a human brain perfectly, but had not connected any input or output. Had not let it see the world, learn and experience, been given senses and time to processes them, then the result would probably not be considered sentient. A small baby or a person with severe brain damage or even brain dead isn't sentient (at least not by most metrics). If the infrastructure is there, but the software isn't running, it's lacking the thing required to be considered sentient.
TLDR: Sentience is an emergent property of a large and complex system. Proving that a small part of that system isn't sentient isn't the same as proving the whole isn't sentient.
LLMs still aren't sentient tho, I disagree with the reasoning, not the conclusion.