I prefer my view:
We are looking for the wrong things. (more accurately, what we are able to look at gets attenuated too much to be useful, unless the aliens are literally burning up whole goddamn suns to try and talk to us.)
Any civilization that is as advanced as we are would have their radio frequency emissions attenuated after just a short (in terms of interstellar distance) radius around their planetary system, simply because of the inverse cube law.
It would become just a bath of random chaotic signals intermixed with the much louder signals produced by quasars, feeding black holes, magnetar pairs, neutron star binaries, et al.Unless they were absurdly close to us, such as in the Alpha Centauri system, we would never be able to communicate with them using the technology we currently possess. James Webb is a fabulous telescope, and has very good IR sensing capabilities, but is not sufficiently large of an aperture to be able to directly scan distant star systems in the manner required to detect thermal signatures from alien species' industrial operations. We would need to create an entire constellation of Webb Telescopes at the Lagrangian point, and use them as a large array telescope to have any chance of it.
So, what about hyper advanced aliens?
Our very limited gravitational telescope tech has
shown there to be a very small, but important incongruity between the speed of Gwaves and radio waves through space. This is because space is not empty: There is a very fine soup of energetic particles all suffusing it, which slow down EM radiation, but not gravitational waves. As such, Gwaves arrive first, and unless they interact with a very large gravitating body, they do not get attenuated by that 'stuff' in the way. This means that a gravitational telescope array would permit FAAAAAAR more clear and accurate scans of distant systems, especially when combined with the fact that Gwaves lose energy in the
inverse square relationship, not
inverse cube, like with EM.
Assuming a civilization could produce high intensity, highly directional gravitational waves, they would be a FAR superior carrier for interstellar communication than EM radiation. Such as for instance,
a GASER Such communication would require precision calculation of time dilation effects between source and destination, and would have to be aimed into regions of space into which the target "Will pass at the time the wave arrives", rather than simply pointing at the target. It would have far higher fidelity than EM communication, due to the lack of attenuation by intervening matter, and the order of magnitude less energy loss over distance due to the inverse square holding sway. It would however, still be effectively "Light speed" communication.
It is important to stress that until the last decade or so, Gravitational Waves were considered "Theoretical", and we had no means of accurately detecting them. Our best instrument, LIGO, is both massive, and low resolution. (It is essentially "A single pixel" sized sensing device.) Should an alien civilization be encoding data in G waves, we would likely not be able to tease it out unless they were sending it as morse code. This is not very efficient as a transport;
Polarization based communication stratagems normally used on laser optical communication would apply to gravity wave based communication as well
(since gravitational waves exhibit polarization), and would permit many orders of magnitude greater density to be transmitted and received, assuming suitable sensors and broadcast equipment.
It is quite possible that the reason we don't see any aliens, is thus:
1) The thing we are able to search for gets turned into a smear of EM radiation that we can't discern from the background.
2) The thing we might be able to search for eventually, and that appears to be a better candidate for interstellar comms, we currently lack the resolution to receive with enough fidelity to tease out intelligent messages.
3) Due to the need for the communication to be directional, we would need to be "Very lucky" to be in exactly the right place and the right time, to intercept a transmission not meant for us, should we have the technology to collect and analyze gwave data at sufficient fidelity.
Assuming that all advanced intelligence must be hobbled by EM communication, like we are, is hubris.
Assuming that just because we cannot detect them, they must not exist, is likewise-- pure hubris.