It could also be that that same species was smart enough to realize that maybe beaming signals out into the wider universe might just be a sign saying, “Hi, we’re idiots, please come eat us!” and use broadcasting sparingly. Or they may have gone to quantum communications instead and don’t have any detectable broadcasting at all.
Terence McKenna has some interesting (and far out) thoughts on the “communication without being detected” concept.
He would use communications that were disguised as “background noise” of space, that could not be detected unless you knew the “code”.