Being very generous, in my opinion, and assuming 1 in 2 systems has a planet/moon that is inhabitable by life as we know it, and that 1 in 2 of those has tool-building life at some point, in our galaxy you get something like 1 tool-building civilization per 600,000 square light-years spread out over 12 billion years.
It really isn't. Do the math, I did (scroll about halfway down): https://www.ryanmercer.com/ryansthoughts/2014/11/30/this-jus...
Being very generous, in my opinion, and assuming 1 in 2 systems has a planet/moon that is inhabitable by life as we know it, and that 1 in 2 of those has tool-building life at some point, in our galaxy you get something like 1 tool-building civilization per 600,000 square light-years spread out over 12 billion years.