The LLM algorithms seem pretty clunky to me, like a hack designed for text translation that surprised everyone by getting quite smart. The reason the human brain is so much more energy efficient is quite likely better design/algorithms. I was watching some video comparing brain and LLM function and almost tempted to try building something myself (https://youtu.be/3SUqBUGlyh8). I'm sure there are many more competent people looking at similar things.