As time goes on, and we find no evidence of aliens, the dark forest model is more and more likely vs. the kindly lumberjack model. In the kindly lumberjack model, we're more likely to detect other civilizations.
Or not. The great thing about astronomical observations is that they can scan across millions of years in a few seconds. We look at thousands of other galaxies, some old and some ancient, but do not see massive extraterrestrial civilizations doing big things. That is pretty strong evidence that there aren't any lumberjacks chopping down stars for firewood.
it's that our notions of what would be useful to look for are to significant extent conditioned on our own level of technology.
There are axioms, for sure; but we are also axiomatically limited in our imagination to that which we have had insight into with so far.
Our surveys to date have focused almost exclusively on the presumption that an advanced civilization would emit (intentionally or as a byproduct) RF in a manner we can detect in the bands it is convenient for us to examine, and focus on from reasonable first principles.
But there are as many arbitrary assumptions or allowances for our convenience or technology in our surveys as there are motivated ones. Arguably more. (I would so argue.)
Not long ago I read that fascinating blow by blow of the zero-day demonstration of using Apple device discovery exploits to own iPhones, so long as you could get close to them.
As interesting to me as the actual exploit mechanics, was the patient walk through of the state of the art of frequency hopping band-sharing error-and-conflict-tolerant protocols matter of factly surrounding in my in my house.
Were I a HAM operator patiently looking for CQ, I might well miss the massive Zoom party going on on the local Wifi. It would be "noise."
I am not making a specific argument, just saying: our own technology continues to advance so quickly at our own time scale,
that the presumption that the universe we can see is "dark" is IMO not just naive but willfully so.
There is much in basic physics we still are struggling with and/or have no plausible model for yet.
So long as that is the case, we don't even know if we're in a forest, let along a dark one.
No. That is radio SETI. The search for life also looks includes Dyson-SETI, the search for megastructures, or other technosignatures, which can have nothing to do with RF.
(1) A galaxy without any supernovas, with all the dangerous stars pushed out of the galactic disk -> the lumberjack scenario. (2) A planet with gasses associated with industry -> technosignature. (3) Unexplained planetary phenomena, starlight doing things that suggest large orbiting megastructures (Dyson sphere territory). ... and the list goes on. Radio telescope SETI is one very small corner in the search for other civilizations.