Yeah, and it must be noted that the grabby aliens idea works best if you consider specifically unaligned AGIs, which I expect would be the most dedicated possible expanders. Other civilizations with more sophisticated values might have plenty of reasons to not grow quite that relentlessly and brutally.
One theory is that we are early in the universe.
See, for example, Robin Hansons grabby aliens hypothesis which goes into why we would expect the universe to look empty from our perspective
Yeah, and it must be noted that the grabby aliens idea works best if you consider specifically unaligned AGIs, which I expect would be the most dedicated possible expanders. Other civilizations with more sophisticated values might have plenty of reasons to not grow quite that relentlessly and brutally.