EDIT: Re: energy efficiency: the problem is that humans are too energy efficient. Your brain can keep functioning after 3 days of running across the Savanna without food, which is (a) awesome, and (b) not really helpful nowadays. The cost of this is that you can only usefully use a little energy each day, say 4 or 5 burgers at most. AGI prototypes will usefully slurp in power measured in number of reactors.
A choice quote:
In contradistinction to this orthodoxy, I find the following five heresies to have more evidence to support them.
Intelligence is not a single dimension, so “smarter than humans” is a meaningless concept.
Humans do not have general purpose minds, and neither will AIs.
This is awfully similar to "On the Impossibility of Supersized Machines" (https://arxiv.org/pdf/1703.10987.pdf).
EDIT: Re: energy efficiency: the problem is that humans are too energy efficient. Your brain can keep functioning after 3 days of running across the Savanna without food, which is (a) awesome, and (b) not really helpful nowadays. The cost of this is that you can only usefully use a little energy each day, say 4 or 5 burgers at most. AGI prototypes will usefully slurp in power measured in number of reactors.