And while fictional evidence is still only fiction, the way that book ends strongly hints that they got something crucial wrong. They weren't running "on dust"

And while fictional evidence is still only fiction, the way that book ends strongly hints that they got something crucial wrong. They weren't running "on dust", they were running in the simulation of some being that's particularly interested in universes that embed simulations of sapient beings. Such as their own, and then later the "experiment"...