Since this is part of an MIT lecture series on AGI, I think the GP is sort-of justified in also asking where that part is.
The reason? Otherwise why build it? Yes, there are cases where AGI as subhuman-level intelligence would have utility, but the remaining cases are far more numerous and have far more utility.
But why do we want to replace ourselves? Do we just want the machines to do everything for us? Take care of us like we're pets?
I for one hope they can fortify my deep solipsism with more detail, my own personal paradise Matrix. Or maybe they can just take care of me while I waste away on drugs, ensuring no negative externalities.
>Otherwise why build it?
Because it would be better to send robots into dangerous situations that it is to send human beings.
Once there's a way to train a general intelligence it's likely hard to contain the improvement - that's why the goal alignment problem is important. Even the current human architecture running at a billion operations per second instead of its current 100 or so would be a problem.
Human general intelligence is constrained by things like power consumption available via eating or needing a head that can fit out of a birth canal - AGI constraints are a lot less limiting and AGI can improve faster.
To put it into perspective if you can run the human architecture on an AGI at a billion operations per second it's like compressing a historical human civilization of learning into a couple hours.
Maybe for some reason this learning process will be slow or maybe there's some reason why it can't scale up quickly, but based on the learning speed in narrow areas that seems unlikely.
There's also the fact that natural selection which is a relatively brute force sexual selection mechanism still results in general problem solving brains being everywhere - it doesn't seem like something particularly rare.
Maybe a single human, but can you run an entire world civilization and it's environment (basically Earth) in a sped up manner? Because one super fast human-level intelligence is still constrained in a way that all of civilization is not. What is one human sped up a billion times? Is that 1 billion humans? We already have several of those units operating around the clock. And those units have access to the world's resources, whereas one sped-up mind will not, unless it can gain control of the world.
You may not need that much access to the world to learn/infer a lot about it [1] and if a superintelligent AI needed access to more in order to achieve its goal it'd probably be able to get it.
[1] https://www.lesswrong.com/posts/5wMcKNAwB6X4mp9og/that-alien...
Though many approaches to “exactly-human intelligence” would just result in humans that happen to be robots, and we probably don’t want that, especially if the point is to make them do all our work for us.
I don’t know how to refer specifically to the alternative, though—an intelligence that can solve “human-hard” problems, without needing anything like sentience or self-determined goals/desires that would push it toward wanting things orthogonal to its designed purpose. Human-adjacent AGI? Human-competitive Tool AI?