The maximum numbers of bitcoin to be mined is 21 million bitcoins. Bitcoin can not be used as money by the whole world because it has a maximum cap. My opinion . What is your stand ?
Thats why bitcoin price is the most expensive coin in cryptocurrency.
With very limited supply, bitcoin has a high value so the peoples will buy in fractions.
therefore, the whole world still can use bitcoin, a coin that have the highest market cap because its value.