idk ^~^
id like to think intelligent life exists. maybe it's like stellaris and there's an advanced civilization monitoring us but we happen to be within their galactic borders and it's commonly practiced to steer clear. Maybe it's an empire where interfacing with other species' isn't a thing and it's inhabitant and predominant species is the kind that obeys all designations when given by a higher power as it was what led them to the stars to begin with.
or, maybe the answer is in frequencies. Wave-particle duality posits that being able to pass through an energy barrier is possible with the proper wave frequency of the particle. there are lots of theoretical limitations for it.
Maybe the biblical firmament is real, and beyond is the realm of other gods of other civilizations or universes, each keeping us out. i mean, i am a Christian, but I do like to be curious and test my faith with theory and the like :3
Maybe we lack the technology to intercept their transmissions. Perhaps they don't use technology that is discernible to us, and instead appear as cosmic phenomenon or enigmatic occurrences