This depends crucially on your definition of AGI. LLMs are more like a mathematical function than they are a conscious being. If, in your opinion, AGI could be realized as a input/output function with no changing internal state, like a lens or a lookup table, then we could say LLMs could be an element of AGI. But if, like many of us, you believe an AGI needs a changing internal representation of the world, and an ability to mull over prior knowledge and incorporate new inputs, then LLMs are at best only a useful component of AGI. Maybe like the retina of the human eye plays some role in human visual intelligence.

The fact that LLMs appear so intelligent to humans is really a reflection of our inability to imagine effects of scale. We can understand simple linear predictions as trivial calculations, but when language-based pattern discovery is many layers deep and those patterns are combined in nontrivial (but non-intelligent) ways, we project intelligence onto the result.