At the current moment or even in the upcoming year or two, for me there is no way Ethereum to replace Bitcoin.
For now, Bitcoin is not only the main coin in the Crypto World. Bitcoin is the trade mark of the Crypto World. If Ethereum became bigger than bitcoin in the next 1-2 years I am not sure if this will be ok for the whole Crypto World as marketing, because a lot of people won't get in the crypto, because they simply do not know about ethereum, but everyone knows Bitcoin.
The marketing aspect of the situation before the whole World is very important guys, because if the crypto stays at this levels it won't develop. Crypto must grow and the only way is by making more people to have faith in it and for the moment, for good or bad, people know more for Bitcoin as coin than Blockchain as technology...that's the truth...