bitcoin is the king because of a high price and also how the popularity of bitcoin is popular with many people, so I think it's a natural thing for bitcoin if bitcoin becomes king.
Bitcoin is king among all other cryptocurrency because of its market price. In this time one bitcoin is equal to approximately 6400 dollars and no other cryptocurrency has such market price. And Because of this market price many investors use it for investment purposes and bitcoin is the first virtual currency which accept by multiple government and by many multimillion companies which also help to boost up bitcoin popularity. In comparison others cryptocurrency its user number are high and its is also use for various others purpose and these things make it king among all other cryptocurrency.