The Fermi Paradox seems to rely on other civilised aliens being detectable. But why would they be? Unless they're emitting a LOT of radio waves (and we've swi

The Fermi Paradox seems to rely on other civilised aliens being detectable. But why would they be? Unless they're emitting a LOT of radio waves (and we've switched mostly to streaming not broadcast) OR doing some giga engineering, what would we see that we're currently not seeing? Maybe in 50 years, assuming we have the telescopes to look for cities on extra-solar planets, we will find them everywhere. But right now, the absence of either high powered radio or Dyson spheres does not mean the absence of civilisation.