But if it is true we're literally already dead since we've been blasting radio waves into the aether for over a century

That's the thing that annoys me most whenever I talk to someone who can't shut the fuck about the dark forest and wants to frantically shut down all attempts to communicate with possible aliens.

And it's not even just the radio waves. Apparently they become too diffuse and garbled to detect easily after a few hundred light years anyway. The real problem is the fact that any alien civilization with both the will and resources to take us out from thousands to millions of light years away would have already known about life on Earth for the past billion years. It's no secret. Whenever the Earth passes in front of the Sun, anyone within that line of sight observing with a sufficiently powerful telescope will clearly see spectroscopic evidence of both methane and oxygen in the atmosphere. That sort of atmosphere just doesn't exist naturally in equilibrium without life constantly replenishing it. It's what astronomers call a bio-signature. So these potential omnicidal aliens have had more than enough time to throw a rock at Earth at 99% the speed of light, and that rock has had plenty of time to get here.

Maybe they only want to kill technological civilizations? Well, in that case they'd be monitoring planets known to support life, waiting for something they consider a threat to evolve. Clearly Earth would have been one of those planets on their watch list for a very long time, and by now their spectroscopy data is showing them all of the weird shit we're extremely suddenly dumping into the atmosphere, an obvious techno-signature.

So hiding from them is very clearly not a productive use of our resources. If the dark forest really is the solution to the Fermi paradox, then we have a near light speed rock with our name on it no matter what we do or don't do. Stealth does not exist in space. So we might as well just try to be friendly and open to any other alien civilizations that might be out there.

Dark Forest Theory is probably total bullshit since it just assumes alien civilizations will be monolithic in nature or coordinated enough to have a singular response to the presence of any rival civilization

Uh Dark Forest Theory makes no assumption on coordination between alien species? At least the one in the book. In fact it argues the opposite, no coordination happens at all, civilizations just act the way they do because they have no other choice