Your source is... reddit comments??

Source? I'm pretty sure sperm count data at least in the past 20 years has been scientifically sound and that has shown an even sharper drop.

I think you're really over complicating evolution and life to a degree that breaches into the realm of fantasy. Alien life is constrained by the exact some rules of physics as we are. I don't think there's any reason (yet) to believe life as we've observed it on planet Earth is not a common phenomena in the cosmos.

But then you see headlines of 7 different species evolving to basically become a crab. Makes you wonder how often species could convergently evolve into a form similar to ours.