According to me, Bitcoin is the first crypto currency, which has got a good time to become famous. This is just one coin . Etherium is better because it is the only platform for all coins today. Which makes it better.
But still when it comes to the overall statistics bitcoin is still better among all other altcoins even with ethereum. Bitcoin is very much the basic cryptocurrency and ethereum may be widely used but people still tend to favor bitcoin because of its credibility.