Karpathy himself believes that neural networks are perfectly plausible as a key component to AGI. He has said that it doesn't need to be superseded by something better, it's just that everything else around it (especially infrastructure) needs to improve. As one of the most valuable opinions in the entire world on the subject, I tend to trust what he said.

source: https://youtu.be/hM_h0UA7upI?t=973