It is from Crash Course Astronomy. It was used at around the 6th minute and 45th second. Here it goes:
There're a lot of assumptions built into this idea, of course. One is that, well, aliens exist. The next is that they are more technologically advanced than we are. But that makes sense. Any aliens that don't have tech can't communicate with us, so they don't play into this.
What does play into mean there? Could you please rephrase the piece of the text for me?