There are about 100 other parameters whose relative balance determine game theoretical solutions to the problem. And as with many things, Cixin Liu handwaves away all that complexity in service of narrative.
Don't confuse fiction with reality.
Look at the Drake Equation as a much simpler example. Even given its simplicity, small tweaks in assumptions produce wildly different projections.
> There are about 100 other parameters whose relative balance determine game theoretical solutions to the problem.
Name three.
I'm by no means an expert on game theory, but accepting the two axioms that are quite explicitly stated in the story, "dark forest" seems to follow quite naturally.
Not confusing fiction with reality. Simply stating the premise of the novel.
I don't object to anyone handwaving away complexity in service of narrative. Virtually all authors do that. (Two exceptions that come to mind are Tolstoy's War and Peace, and Proust's Remembrance of Things Past.)
But those who don't reach it are exterminated.