I suspect the answer is 2 fold. Firstly as mentioned before we ourselves have been moving from large over the air broadcasts to cables and smaller more targeted signals. That is a huge consideration. But we must consider the vastness. It's fully possible that a far more advanced civilization is using much more targeted broadcasts then we are now. I would like to mention as well that we do have a plausible theorem for ftl drives, the osbatcle is just the amount of energy. Which may sound high to us now, but may become more easily tackled as we advance.
To-morrow, and to-morrow, and to-morrow,
Creeps in this petty pace from day to day,
To the last syllable of recorded time;
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life's but a walking shadow, a poor player,
That struts and frets his hour upon the stage,
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.
Creeps in this petty pace from day to day,
To the last syllable of recorded time;
And all our yesterdays have lighted fools
The way to dusty death. Out, out, brief candle!
Life's but a walking shadow, a poor player,
That struts and frets his hour upon the stage,
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury,
Signifying nothing.
