If Bitcoin is the king of crypto in terms of value as well as the largest market capitalization. ETH is dubbed the queen of Altcoins so after Bitcoin, I believe ETH is crypto worth keeping in the long-term. Therefore, the more valuable the Bitcoin is, the higher the ETH is.
We can say like that, ethereum is the second strongest coin after bitcoin, the daily transaction volume which is always above $ 5 billion certainly makes me not hesitate to make ethereum a long-term investment (more than 2 years).