Ethereum will not die. It will only lose value and another one will replace it.
Think about it for a while: ETH is increasing value because of its over-valued ICO and everytime some of those ICO starts, the ETH network is congestioned and slow.
I'm not saying that we won't see ETH at 1000$+, but it will lose value when some alternative will take place.
Ethereum will not die, it will survive used by those companies that are starting their business on it.
Now I'm looking for some Ethereum alternative
Let's see what Rootstock will bring..