[asou]

What if Radio waves simply don't work the same on other planets .

Or one of the first things civilizations figure out is to not broadcast your presence.

Or ... Everyone else in the universe found peace by stopping at the stone age , before all this social media made us miserable.

It's just conjecture, but I imagine aliens exist, but they might not even be in a form re recognize.

[enkid]

Well, to pick some nits, if radio waves didn't work the same way, that would be a pretty fundamental shift in physics, to the point of throwing all our assumptions out the window about our observational evidence.

[_mkef]

We're assuming they communicate the same way we would.

I'll make up something scifi like. On planet x they use short term Seismic wave to move data around. How would we on earth ever pick that up