Etherium is a reliable crypto currency, but investing all your money in the Etherium is too risky. The situation on the crypto-currency market is unpredictable and can change in any direction.
Of course, I understand your fears and springs I know that the risks in the crypto currency business are very large. But if there are many other coins that can die, then with the etheric it can not happen. Virtually 90% of all coins are created by the etherium protocol.