How can we confidently state we know ChatGPT doesn't use neurological mechanisms, when we don't yet completely understand our own neurological mechanisms, nor emergent mechanisms that may be at work within ChatGPT?

At the same time, we can already comprehensively model some biological neurological systems in their entirety, in silicon. This will continue and the human mind will not be immune to such progress, making the question important.

I see it as a question that cuts to the core of the matter - long-standing, unanswered philosophical questions:

What does it mean to "perceive"? Can a machine be conscious? Are our biological processes meaningfully differentiable from equivalents when mimmicked by a machine? Are our "perceptions" special? Or not?

Putting the point another way:

We can't be objective about "perception" from within the constraints of perception.

While we routinely "imagine" an objective reality that exists beyond our perception, that we believe our perceptions reveal, there is no way to conclusively prove that's actually happening. Possibly, ever.

(As for the side note: I genuinely interpreted it that way, hence the word "seem", I didn't think about whether or not you'd missed it. I too assumed a conversation precisely unlike reddit... my default assumption here.)