That is clearly evident in the current market conditions when the price of Bitcoin rises another cryptocurrency will also rise. That proves Bitcoin is still number 1. Apart from being the first crypto currency most people also prefer Bitcoin because they have benefited from investing in that currency.
Many are confidently have bitcoin because it has more potential than the other coin to grow in the market. It is the first coin being introduced in the market and popular for investors. People believe on it that it will continue to grow after a lot of fall. They are trusting it because it is beneficial to have it.