Time is big too.
Given the size of the universe and the fact that we’ve been around for a tiny blip of time, what are the odds that two life forms with different origins are close to each other at the same time?
Yeah. And it’s an even smaller blip when you about how little time we’ve really been able to detect anything outside our planet. Plus of course anything detection would have to travel too. Let’s say one of our early high powered radio transmissions from around 1900 got detected by somebody on its 100th anniversary, so 2000 (cause I’m math lazy). And those aliens were all “hey, there’s somebody out there” and sent a signal back... well we ain’t getting that signal until 2100, 75 years out still). Space is big, time is big, people and our ability to see and be seen are small.