Why do some people think that other coins will replace bitcoin? Is it because everyone is disappointed with bitcoin? While other coins also have advantages and value is rising, they are not bitcoin rivals. Bitcoins exist longer than any other coin and experience more of a test.
Same reaction everytime bitcoin experiences dip on its price. Many are being disappointed and gets panic. Observing how other coins goes like Etherium where it has gained so much, for sure many thinks that it will dethrone the reign of bitcoin. But in the end, bitcoin will still remain highest for a long term. Stay foot. Though it's not forever or yeah there will be time that it will be replaced by another coin but not too soon.