There is a theory that intelligent beings develop their scientific knowledge thru roughly the same process, eventually reaching a point where a “scientist” does the equivalent of “I wonder what happens if I try _this_...” and the entire planet/system/galaxy ceases to exist. Maybe someone tried it on a remarkably large scale in the center of that region...
Personally, I wonder this: If all races develop machine intelligence to the point that AI becomes hyperintelligent and continuously improving, wouldn’t we see many competing hyperintelligent AIs? Or is that what God is — a group of AI’s that merged?
If super-AI is inevitable, where are previous-civilization’s copies of same?