Did you read the parent in haste or did they edit their post? They said: > [1] It means that civilizations should exist that are millions of years more technol

Did you read the parent in haste or did they edit their post? They said: > [1] It means that civilizations should exist that are millions of years more technologically advanced than us; > [2] and should be leaving telltale signatures across the sky that we'd likely have detected by now. > [3] And the absence of those signs would be relatively strong evidence that life, while common, isn't long-lived. > [4]Suggesting that our demise too, will come before too long. So they were talking about the great filter, not alien invasions, which is what you appear to be replying to.