This sounds like a dismissal of the argument through a characterized straw man.
That is, it seems that reducing the complexity of the brain to "collection of neural firings" is not being honest about everything involved to a much greater degree than saying neural networks are a "collection of statistical calculations".
I too believe LLM's will grow in complexity, but presently I can not even fathom how they can be compared to the complexity of a system such as the human brain.
Totally understandable; I don't think we can fully understand the human brain, using the human brain. We can understand its principles (firings and chemistry, structure and specialized areas, etc) but otherwise it's a capacity problem.
And while I can't fully understand myself, let alone another person, I definitely enjoy talking with people and sharing thoughts that I realize I wouldn't have had on my own.