Bitcoin is mother all crypto currencies. If you follow the flow bitcoin dominates the price of all other crypto currencies. U might see ETH price is $3k or $4K but BTC price for ETH didnt cross .0.08 BTC but in the last bull run it crossed .01 BTC so price is purely determined by bitcoin only!! Yep ETH has more use cases but that doesnt mean it can overtake bitcoin and BNB is still a baby