> Is the key idea here that current AI development has figured out enough to brute force a path towards AGI? Or I guess the alternative is that they expect to figure it out in the next 4 years...

Can't answer that question, but, if the only thing to change in the next four years was that generation got cheaper and cheaper, we haven't even begun to understand the transformative power of what we have available today. I think we've felt like 5-10% of the effects that integrating today's technology can bring, especially if generation costs come down to maybe 1% of what they currently are, and latency of the big models becomes close to instantaneous.