I think bitcoin is most known/popular coin in cryptoworld. It gets more attention because of its features, and price which attracts more investors when it reached $20k, also in addition is because it is the pioneer of all cryptos that gives it more advantage from other cryptos.
It is the first cryptocurrency success and by extension has captured majority of the cryptocurrency market as its market volume against the others attest to this fact and so it has withstood the test of time and hence more popular than the altcoins.