I think that Ethereum will be very difficult to fight with BTC. BTC has so many fans. But second place belongs to Ethereum. And even if people say that there are so many platforms similar to the Ethereum. Ether is the most popular.
But then there are also many many coins that are like BTC. BTC has the advantage of being first and that is basically it. ETH offers advantages and was very closes in overtaking BTC in 2017, but BTC was able to bounce back up.
I don't think ETH will ever overtake BTC, but I believe BTC will lose it's 1st position in the next years to some other competitor.