Organic adaption and persistence of memory I would say are the two major advancements that need to happen.

Human neural networks are dynamic, they change and rearrange, grow and sever. An LLM is fixed and relies on context, if you give it the right answer it won't "learn" that is the correct answer unless it is fed back into the system and trained over months. What if it's only the right answer for a limited period of time?

To build an intelligent machine, it must be able train itself in real time and remember.