It shows something about the game, but it's clear that humans don't learn in the way that alpha zero does, do i don't think that alpha zero illuminated any aspect of human intelligence.
I think that fundamentally the goal of research is not necessarily human-like intelligence, just any high-level general intelligence. It's just that the human brain (and the rest of the body) has been a great example of an intelligent entity which we could source of a lot inspiration from. Whether the final result will share a the technical and structural similarity (and how much) to a human, the future will tell.
In principle you are right. In practice we will see. My bet is that attempts that focused on the human model will bear more fruit in the medium term because we have huge capability for observation at scale now which is v. exciting. Obviously ethics permitting!
Not sure if I am reading you correctly but to me you basically are saying "we have no idea but we believe that one day it will make sense".
Sounds more like religion and less like science to me.
I guess we could argue until the end of the world that no intelligence will emerge from more and more clever ways of brute-forcing your way out of problems in a finite space with perfect information. But that's what I think.
But humans could learn in the same way that AlphaZero does. We have the same resources and the same capabilities, just running on million-year-old hardware. Humans might not be able to replicate the performance of AlphaZero, but that does not mean it is useless in the study of intelligence.