This is purely wild speculation, of course, I only have access to the same information everyone else does, but my guess is that there are about a thousand species in the galaxy right now interested in and capable of interstellar travel and/or communication. We are probably the newest and least capable. That works out to about 1 per 100,000,000 stars.

If all of these communities are currently engaged in ambitious SETI programs, both active and passive, it's still highly unlikely any two will stumble onto each other, even if they search for a million years (I believe that to be a reasonable guess for a species lifetime).

I also believe there are natural, fundamental limits to technological development, i.e, there are no Type III civilizations. (Astronomers have yet to identify any activity which cannot be attributed to "natural phenomena".) Space is a lonely place.