In Classical times, being "one in a million" at something meant having about 170 peers in that field, spread out all over a world that took months or years to traverse such that the chances of directly interacting or competing with one was next to none. Even by the Renaissance, when "one in a million" meant about 500 peers, it remains remarkable that, for example Leonardo Da Vinci and Michelangelo interacted and had a direct rivalry.
Fast forward to now, with instant communication and every "one in a million" person having nearly 7,500 direct peers, all able to interact and compete globally. Maybe you excel at something that would have had you lauded as a genius and going down in history for all time 500 or more years ago. Now you are lost in a crowd that would fill a small stadium.
If you are louder, more obnoxious and more ruthless at self-promotion you might stand out. Problem is, that makes these awful things the only talents that count. And there are people with no talents whatsoever other than being louder, more obnoxious and more ruthless at self-promotion who will drown out not only their peers, but people with far more to offer.