I had a similar insight (blog post: [link redacted]).

In a very unscientific way, I would say that the LLM is not the whole brain, it's part of it and we are still in the process of simulating other parts. But it does seem to me like we've solved the hard part, and it's astonishing to me that people like authors of this article seem to think that the current state of things is where evolution stops.