Bitcoin is not popular because it is the first. But it became famous because it has the right flavor that has attracted supporters from all over the world. One feature of bitcoin is its decentralized system wherein there is no centers. And later on when the price keeps rising up more people comes in to invest to make more profits. But before other reasons came about it was the decentralized feature of bitcoin that became the primary reasons why it is being advocated by people. But as bitcoin become popular people were not coming in because of decentralization anymore but on more money matters and stuff. But it doesnt matter what makes bitcoin popular but the most important thing is that it rises in value and we can have more profit.