A thousand and one days in the life of a turkey--i mean, human civilization
Arguments that rely on gdp historically being tightly clustered around a small number miss the obvious jump-diffusion nature of the claims being made here. It's not a draw from a normal distribution. It's a value you've ever seen before because the distribution isn't what you think.
The expected value of the product of two independent random variables is the product of the expected values of each; this concludes my proof that betting everything on each round is expected value maximizing in a finite game (and infinite too, if you adopt the common ways to make "infinite" precise). I'm surprised the dialogue got that far without this being brought up!