Simplifying things to this degree can show how you get from A to B.
We don't know what 70s AI and ChatGPT will evolve into. That's why everyone keeps debating and prognosticating about it, because nobody actually knows. But whatever people mean by AGI, we don’t know if it will or can evolve from the AI platforms that have come before.
We do know that the thing that evolved into ChatGPT is entirely different from primitive cellular life, so there's no reason to believe that ChatGPT will keep evolving into some kind of humanistic, self-aware intelligence.