Explain how time matters. You are saying that because of "time", these races would be way too far apart to interact with or discover each other.
Because each civilization would have a limited time to search or be found within their "shelf life."
Let's say the first intelligent species in the whole galaxy arose on a system where our solar system is today. Like us, their planet took 4 Billion years to produce them, and then, against all odds, they went out spacefaring around the galaxy, exploring, mining, conquering new worlds, searching out new life, yadda yadda yadda, for another BILLION years.
Then they moved on... Evolved, either up or down, transcending into a pure energy form or back down into primates, or whatever... Their civilization somehow fell... Many scientists think this amount of time could be very small, such as mere thousands of years, not even a few million.
Then many
Billions of years later, their sun went Nova, (as did all the stars in the galactic arm, destroying all evidence of their existence) and then turned to nebulas, and then new systems, and the systems formed new planets, and that's where Earth finally entered the scene, 4 Billion years ago.
Of course some of that old race could have decided to ditch the milky way and travel for billions of years over to the Andromeda galaxy, and assuming they can stay fueled and not too bored on the journey, they could still be alive over there right now... But not as likely here, because of the vast amounts of time.
I'm saying time isn't even a factor if these other civilizations are truly advanced. That's my argument here, sorry if that wasn't clear.
If they arose 12 Billion years ago, and had no problem travelling forwards in time 12 billion years, what, exactly, would be their incentive to pick right here and now to stop and look around?
Civilizations aren't permanent. Macro-evolution changes happens in mere thousands or just a few millions of years. -With technology, who knows, maybe only 200 years from now the human race may no longer be interested in the physical form
at all.
It's a pretty fair bet that once we've mastered technology (including wetware) we'll yearn for something better than the physical, or be literally bored to death.
So the odds are that we won't find anyone, not during the window of time we're searching for them... This is all just one variable within the Drake equation.