Earlier quoted context omitted.
One major weakness of the Dark Forest hypothesis is that it presumes the bad guys have had interstellar travel for a long long time ... and yet in all that time they have never come to our system and left any traces behind. They didn't do anything bad to us for 4 billion years, but now they're going to do bad things because we have radio?
For me, the Dark Forest hypothesis is very probable. However, the whole book series assumes that interstellar travel is possible for advanced civilizations. What if no new physics is discovered, and the only way to accelerate/decelerate is to throw a mass in the opposite direction? Maybe all advanced civilizations in the Milky Way are limited to their planetary systems.
If you could cryosleep, lived for millions of years, or were an AI that could just turn itself off for a while, you could go to the stars using simple chemical propulsion. No physicists’ nightmare torch rockets or warp drives required.
The crazy physics requirement is to enable interstellar flight within natural human life spans. It’s probably easier to extend that or figure out how to hibernate or become AI than it is to build an antimatter rocket or bend space time (if that is even possible).
I doubt the dark forest because Earth has been broadcasting that it’s a likely biosphere via its albedo absorption spectrum for over a billion years. If you are a hyper paranoid alien you should just blast every biosphere to kill any possible rival before it even evolves.