No ET! Ever?

[Jehanne]

Hence unless we blanket the sky with signals, it would be very tough for us to send any short pulse signals in such a way that it would arrive at the same place and time as the target.

As I pointed out earlier, the Wow signal may have been such an interstellar beacon:

Other hypotheses include a rotating lighthouse-like source, a signal sweeping in frequency, or a one-time burst.

https://en.wikipedia.org/wiki/Wow!_signa...27s_origin

Again, in a radio transmission, one is faced with either a directional antenna (such as AM radio) or an omnidirectional transmission (such as FM).  The Sun is omnidirectional, but per Einstein's famous E = m * c^2, there is no way that we or anyone else in the Universe will ever be able to generate the equivalent energy of 10,000,000 nuclear bombs per second.  And, so, a directional transmission is the best bet, but the more narrow the transmission (such as a laser), the near certain result is scattering and/or defection of the beam while it propagates the tremendous distances of interstellar space, and given the 300 or so billion stars in the Galaxy, where does one point the beam to?  In addition, someone on the receiving end has to be listening, and we, as a species, are simply not doing that.  The Ohio State Big Ear telescope is now a golf course!

And, so, the conclusion that ET is nowhere to be found because ET does not exist is at least premature.