A civilisation billions of years more advanced than us should surely be putting out some sort of signal, intentionally or not, that they exist, right? And yet we've never seen any kind of signal like that. Space is incomprehensibly large and empty, and while I also absolutely believe that there is some other kind of life in the universe, the fact that we've never detected any means they've probably never detected us either, so there's no reason they would be coming here