This is one answer to the fermi paradox that makes no sense to me. If we did live in a dark forest universe where everyone was hiding from some oppressive existential threat, how would any of the civilisations learn about it?

They would need to be in contact with one another to discover that other civilisations were being wiped out, but for that to happen, the wiping out civilisation would have to be able to find them as well. If they destroyed civ A, they’d definitely be able to find references to civ B in their ruins, somewhere. I see no mechanism by which a civilisation could observe this enemy in action without being detected.

Unless someone has come up with an answer to this issue, in which case I’d like to see it.

Also, if you can detect them, just telling them that you’ve detected them should change their strategy, because if a basic civilsation like ours can do it then they’re not actually that safe by hiding. The dark forest seems like a really fragile arrangement.