I wouldn't say it's gonna destroy Bitcoin, but Ethereum is fantastic because it has not only been out there for long time as the #2, but also has an actual use (differently from bitcoin) and in terms of usability is better than bitcoin and improving every day thanks to active developer team and side projects.
Wouldn't call Ethereum "The new BTC" but definitely the second best coin out there.
I can say Ethereum is the also the best coin at this very moment it has done a lot of challenges through the years. As we can observe it is still existing and stands firm even there is bitcoin. Yes, Ethereum I can say it is the second one of bitcoin but it cannot be the new BTC.
I agree ETH is a good coin and has battled and is now worth something, but it cannot replace bitcoin ever because bitcoin is still the best coin for many people and for me as well.
ETH will surely rise in the future because many coins are based on it so it will have no problem having support.