The Fermi Paradox may have been intended to question basic assumptions and examine the factors related to colonization in the galaxy. To begin, the paradox statement is, presumably, where are they? Where are these colonizers and why haven't they been here? Lets assume that everything we currently know regarding the physics of the universe, is also known by another advanced civilization in the galaxy. Even though the speed of light is such a slug, FTL travel is not a consideration. Lets also assume that they have escaped, so far, encountering the great filter. We have no idea how old this civilization is, but we can assume they have reached a state of technological advancement sufficient for space travel. Our own civilization, in its nascent way, is at this threshold.
Among things that have to be thoughtfully examined, are other basic assumptions and considerations regarding the state of this civilization, and the practicality of interstellar travel. Even though we have no knowledge of how the life form of this civilization evolved, we would have to assume that they are of a form capable of developing advanced technology and that they have readily available materials needed to carry on this development. Further, we would have to assume that this civilization would be constrained by the same economic considerations that would restrain interstellar travel, namely the prohibitive cost in resources and time of single mission ventures to reach another star system with habitable conditions. Consequently, we are looking at an advanced civilization much older than ours; a civilization that has likely colonized space rather than ventured to a particular place. And in fact, in achieving such colonization they may not have left their home planet because they have been able to conquer all deficiencies and meet all needs required for this advanced technological state. They may have no need to colonize space, but to colonize a single place.
Deep-space communication by means other than radio is an interesting idea, but one thing that has to be kept in mind. Whatever means is used to communicate across vast distances, the speed of light will be a limiting factor in the time taken by transmissions. If radio is used, we already know that transmissions will likely be in the vicinity of the 21 cm hydrogen-band quit zone. This is because galactic and terrestrial atmospheric noise is minimal in the radio background near the 21 cm radio-emission band of hydrogen. In fact, if we assume our state of radio transmission and reception is equivalent to that of another more advanced civilization, the only question remaining would be how they use radio in communication. What are we supposed to be listening for?
We may wish to consider that among the issues raised by the Fermi Paradox is that other advanced civilizations elsewhere in the galaxy are likely looking for us for the same reasons we are looking for them. They have encountered the same limitations in technology that we face. They have encountered the same limitations in physics, the same limitations in the vastness of the galaxy, the same considerations we are having about the existence of life elsewhere in the galaxy. There is no reason to consider that the Fermi Paradox, and its ramifications, are presumptuous. Rather, the Fermi Paradox simply lays out an array of issues and assumptions, and asks that we deeply think about this problem with careful, unlimited, scientific consideration.