Oh yeah and on top of that the way we detect planets around stars creates a extreme bias on dwarf stars since a positive detection needs a few transits before confirmation of a planet can be made. And since dwarf planets transit within days/weeks sun like stars take around a year so it would take 3 years of observation to find an Earth around a sun-like star. But I have heard science communicators imply that what we have detected so far is representative of what is out there which is absurd.
If FTL is impossible(which I doubt since it's only "impossible" in some capacity in Special Relativity. But Special Relativity does not describe our universe, General Relativity does and even that has limits),then not seeing Aliens is not a paradox at all considering radio waves only go out a few light years, and the distances are just too great. And if there are any Alien probes in our solar system sitting on IO or some moon we'd have no idea since we have only done flybys and never truly scanned the surfaces.