> This motionless destination “without difference”, is also known as heat death, or entropy.

This is BTW not how the heat death would look like. There would still be fluctuations that would, given infinite time, produce almost anything by chance at some point.

This is what the Boltzmann brain is all about: If the universe goes down that path, it is much more likely that what we experience is just a hallucination of a "brain" that spun into existence by chance, rather than all of this being a "real" universe. It's the precursor of the simulation question.