Or by "none exist right now nearby". If there are technological aliens 3 bly away and 3 bya, we won't likely discover their signals. If there are technological aliens 10 ly and 10 ya then we're extremely likely to pick up their signals (if they emit any), but they're not likely to come here -- not anymore than we are to go there. The Fermi paradox is most easily understood as "the probability of two concurrent technological species in different but nearby star systems is vanishingly small".

For all we know there have been thousands of technological species in our galaxy, but never two at roughly the same time and roughly close together, and never will be.