Maybe one day another cryptocurrency can be more popular or more profitable or more useful than bitcoin. But this does not means bitcoin is always number one. As you know bitcoin is the first cryptocurrency, the first original one. That's why bitcoin will always the number one
not just for that, i think the altcoin is following bitcoin in the prices, and bitcoin is the first crypto currency that i know. beside that, first time for most of people know is bitcoin and bitcoin is always in number one position in the market. and yes, bitcoin can buy other cryptocurrency with cheap price and it makes bitcoin as the main purpose for people when they use bitcoin in trading.