I don't see any reason why ETH should die. It's basically too big to fail at this point. Even when there are coins that do everything better than ETH, Ethereum will still stick around.
Purely because it's widely accepted and well known.
True, ETH will be hard to die because all new project developers are always using the ETH platform to build their new tokens, with such a thing clearly will make ETH tokens always hold a good position in cryptocurrency.