A billionaire is worth 1,000 million dollars. If there are 2,895 of them, that’s equal to 2,985,000 millionaires.
But with only 21 million bitcoin, that’s 137,000 millionaires— per bitcoin. And that number gets much higher if you divide by the available supply not the total supply.
There’s never going to be enough bitcoin for the millionaires to own even one, if they all wanted to.