I think you’re drawing the opposite of the logical conclusion.
Based on what we’ve seen of humans, as a violent civilization becomes more advanced, a progressively smaller number of hyper-violent individuals are able to do progressively more damage.
It would take a medieval army days to do the amount of damage a WWII bomber wing could do in 5 minutes.
All of the people in history couldn’t have done the amount of damage a few thousand would have done, had we had a nuclear war in the 60s.
50 or 60 years from now - or sooner - a small lab of determined scientists - perhaps a dozen people or less - will be able to tailor make a possibly unstoppable virus and release it on the world - imagine if the Nazis had possessed a complete understanding of the human genome.
Every advance of a violent civilization increases its chances of meeting a violent end.
I could be wrong but, it makes perfect sense to me. Much more than the opposite, anyway.
After thinking about it I think you are right that we are much more likely to kill ourselves than be killed by aliens. Another risk is robots/computers once they exceed human ability and can manufacture themselves. Like humans did they are now evolving fast on the battlefield. If the rule that only one advanced intelligence can exisit in a domain is true, the robots may compute their only option is to kill us off and we will be unable to stop them.