The reason why Bitcoin is the number one cryptocurrency is pretty simple: It was the first one. This first mover advantage persists, because Bitcoin quickly established the biggest support both from users and from developers. Having the biggest user and developer base maintains a strong network effect, that tends to draw in more users and developers, because the system appears attractive and is well-established as a payment system.
For any altcoin to compete with Bitcoin, it would have to offer something revolutionary new and useful, that can't be implemented by Bitcoin. Today's altcoins are mainly a testing ground for new ideas, that will end up being added to Bitcoin if they are good, leaving the altcoins that first introduced them behind (a current example for could be rootstock vs. ethereum).
ya.ya.yo!
Indeed. Bitcoin is really the first cryptocurrency to be established that is why its rise is really that fast because it offers people a lot of features to explore which is really beneficial and useful on their part. Bitcoin being decentralized enables us users to manage our own earning without the concern of government and banks. The capability of our money to grow is always visible because its price is continuously changing enabling us to gain by just simply saving and holding into it. Those features attracts people to get engage with bitcoin and that is why the demands and usage of bitcoin is rising that is the main reason I can see why bitcoin is that powerful. Because of the people behind it.