Im more surprised that Ward-Kovalev didn't draw better given the controversial nature of the fight and the subpar buy rate. That drew 834k, which means the grand total of people that saw it via official channels was only approximately 1 million (and that's assuming zero people double dipped by buying the PPV and watching the replay).
Your hardcore sports fan in America has not the slightest clue who either of them are. Your most hardcore of sports fans in America usually have only watched one fight in the last 5-10 years (Floyd/Manny). Boxing fans in America are a very special kind of rarity compared to almost every other sport you can name.