Actually impossible no. Just improbable. Looking at the math, the famous Fermi Paradox asks an important question: why aren't we detecting any sign of any other civilization? According to the math, there should be thousands in our own galaxy. But maybe life it's so rare and the conditions that allow it to evolve to become sentient, and then develop technology are so unlikely, that we are the only one. Or at least the first one, there could be others that will appear in the future. Maybe we will be the technological advanced aliens to them.

But as a personal opinion, it will be sad to have all this empty space just for us. And we keep waging wars and murdering one another for something so trivial as money and power.