Aliens could also be so advanced, the way they communicate is way beyond anything we’ve even thought of yet. It would be like trying to pick up color tv signals on an AM radio.
They also could be so far above us, we’re not considered worth talking to, if they notice us at all.
This is my suspicion. I think that many species either leapfrog over long-distance electromagnetic communication for more advanced science, or they are ‘tuned in’ to something more like telepathy. But that would get into philosophical theory of mind, and this is a UFO thread 😉