I think it is all about the eras? Don King did more, probably and it’s likely relatively speaking to the reach of Richard he did as much. I’m not sure this isn’t something I know much about.
Boxing was more popular in Rickard’s day but the media reach was immensely smaller. In spite of this, reports of Dempsey’s fights as they happened reached as far afield as New Zealand! That King had Ali as well in his time, & later Tyson, helped him at least as much as Dempsey’s fame personally helped Rickard. I’d have to say given the lesser media reach Rickard deserves the nod.
Rickard progressed the popularity of boxing by magnitudes. He created opponents from whole cloth, created compelling narratives, and always won the event. King evolved well with the changing landscape, from 70's closed circuit shows to PPV to the decline of the heavies, the influx of Latino fans and fighters, to recapturing Tyson... A lot to be said for his acumen and vision, if not his ethics. I would say Rickard was the true innovator. King was the true operator.
