He didn't KO Max cuz Max is tough as nails. He didn't KO Nate for the same reason, although he dropped him numerous times. He didn't KO Floyd cuz it was a boxing match against Floyd. Everyone else on that list he absolutely mangled, several of whom were absolutely KO'd. Eddie and Mendes were completely out and Brandao, Siver, and Poirier were beyond fucked when the ref stepped in to save them. Don't forget Brimage and Buchinger on the KO list, too.
Conor hits harder than everyone that counts at FW and LW, along with being the best technical standup fighter. He's not necessarily the best fighter in those divisions, but he is the best striker. Or he was before he decided to take a couple years off.