The Simulation Argument

No.12996280 ViewReplyOriginalReport
>https://www.simulation-argument.com/
>This paper argues that at least one of the following propositions is true: (1) the human species is very likely to go extinct before reaching a “posthuman” stage; (2) any posthuman civilization is extremely unlikely to run a significant number of simulations of their evolutionary history (or variations thereof); (3) we are almost certainly living in a computer simulation.

I don't get how this guy comes to the conclusion that if (1) and (2) are false, then (3) must be true. I find it perfectly reasonable to propose that if the human species will not go extinct and will in fact run simulations of its evolutionary history, that this simply has not happened yet and we are not living in a simulation.