Earlier quoted context omitted.
This is not a tenable argument if you are a materialist. Either you accept the idea that human sentience is attributable to a soul (and therefore cease to be a materialist), you decide that the outward appearance of sentience is sufficient (which you might find to be troubling due to its potential implications for the insane), or you say that sentience is unknowable. There's no fourth option.
The True Materialist will tell you that it's biological cells and DNA that gives rise to sentience. AIs made from artificial neural networks are actually not quite the materialistic thing. It's some spooky emergent property that doesn't depend on material substrates, you can run an AI on a Nvidia card for sure, but you can also run it in your head (theoretically, if you live forever). Or at least with the assistance…
The question, then, is: what are the properties of the system that the term describes?
In this case, it looks kinda like: memory, self-awareness, and understanding. Memory isn't a question - it's possible for these things to remember (even if sometimes that memory is in the form of access to data on the internet). Self-awareness is trickier - but by most measurable schema, the machines seem to be doing as well as humans do in this regard (they can describe themselves and talk about their place in the world in context). Understanding is a topic of hot debate - but I think it tends to fall to the same problems as that of sentience generally; that is, we have this concept of what understanding is, and we know enough about how LLMs work to say that they're not the same, but if you start poking at how to measure it, we're back to square one vis a vis what's apparent might not be what is.