If I get to define "consciousness", sure. I'd go with "capable of building a general-purpose internal model of reality, ability to reason on that model (guess about causality, extrapolate, etc) and update it plus some concept of self within that model". I would argue that current generation LLMs already have those, but you could certainly argue about lots of nuances, and only the whole loop (inference plus training) even qualifies.

> You don't have a proof of possibility either, you have no idea how a brain works and you're just postulating that in principle a computer can do the same thing.

Essentially yes, but I think this argument is really weak; we arguably have some understanding of how the brain operates, and LLMs are basically our best attempt so far to replicate the general principles in silicon.

But "understanding" and "ability to replicate" are obviously very different-- you wouldn't argue that we don't understand human limbs just because we can't build a proper artificial arm, right?

Assume we made some breakthroughs in online learning/internal memory modelling over the next decades, and built some toy with mic/speaker/camera and basically human cognitive abilities: would you hesitate calling such a thing conscious? Why?

I think almost everyone has lots deeply embedded, unscientific notions about the human mind, but the cold hard fact is that simple evolution basically bruteforced human congnition from zero, so there is no reason to me to assume that we can't do the same with several billion transistors doing mostly linear algebra.