Only 21 millions people out of 7+ Billions people to become millionaires are being created in public
You've heard it right. There are currently 21 million millionaires are being created in public.
Hint: 21 million bitcoins.
I don't understand OP's statement.Is there any central authority which dictates that one person could have only one bitcoin so that when bitcoin's price reaches a million dollar,there would be total of 21 millionaires.But that's not the case.Even one person alone could hold 100 bitcoins and another person could have 0.5 BTC.So,the total number of millionaires due to bitcoins may vary.