Sure, I think my various hedges that say "so far" acknowledge this. I still think 80 years is a success story given the usual patterns of humanity.
This is a US centric view. You define success favorably to your argument. The world has not even been at peace since, with the sole nuclear weapon user being involved in a significant number of consequential wars after WWII. I guess you mean no conflict between great powers on a global scale, which I doubt anyone seriously considers stable and long lasting. But if there were total peace, 80 years wouldn't be such an outlier, given we've had long periods of peace before nuclear weapons as well. You might be right, or you might be wrong, but your reasoning isn't quite there yet.