Thanks—if you do a search for “grabby aliens” there is a professor who talks a lot about the topic.
He is convinced there are predator aliens out there who conquer and destroy potential rivals in large numbers.
It is sort of a Darwinian take on alien life.
The logic of that view is that the only alien civilizations that could survive would keep a super low profile—camouflaged in their environment and/or using technology to mask their presence.
I am convinced that if our species were space-faring we'd be one of those.