As far as I can tell, Dark Forest Theory has one flaw: concurrence. To be subject to the threat of DFT, our civilization has to be concurrent with that of another race…and when to comes to cosmic time frames, the rise of our own civilization is happening in the cosmic blink of an eye. The threat not only has to be spacefaring in our own (rather remote) neck of the galactic woods, but also must be relatively concurrent with our own.

https://medium.com/@glennrocess/the-fermi-paradox-the-martian-conundrum-and-a-flaw-in-dark-forest-theory-73651558ad9d