On the one hand, I see that it is possible for Ethereum to overtake Bitcoin as it is more innovative and it is capable of performing much more functions than Bitcoin. On the other hand,people trust Bitcoin more than any other currencies, they use it not only as investment,but also as a means of payment, so I it gains more and more popularity within time. The question is whether this tendency will continue or not.
It does not matter at all if ethereum can do one thousand different things and bitcoin only one, bitcoin can do that one thing in a masterfully way and that is more than enough for bitcoin to remain at the top, we are in times of crisis and what it is needed more than ever is a strong and hard currency, and bitcoin does exactly that, so the demand for bitcoin will always be there as there is no coin that is anywhere near bitcoin when it comes to adoption, while ethereum could always lose some ground against new coins that do in a better way some of the things it does.