Bitcoin having some expertise in it's part as computerized gold offering the tried and true money related framework free from out limited expansion and political mediation. Ethereum developing into world PC a Blockchain based programming dialect empowering code based contract and decentralized application.
It has the first mover advantage to begin with. That is more than you can ever know. Ethereum is now gaining public acknowledgement however when bitcoin first came out and news never even heard of eth and etc people were talking about what the price of bitcoin will be on news and economy shows, which means bitcoin was known by the public and the financial sectors in a longer period of time. You have to consider this and judge two coins on that, ethereum hasn't paved the path bitcoin has gone.
We can say that bitcoin is the father of digital money or cryptocurrency and ethereum is a son.
Then bitcoin has thousands of sons and daughters, lol ? The prime differences I like to mention, supply limitation. Etherium does not have any cap on its total supply. It is gaining popularity due too its capability of providing easy platform for tokens but already many coins are having that capability hence etherium is not unique whereas when bitcoin was introduced it is am unique way of payment system.