It's not about Bitcoin. It's not about Ethereum.
The technology behind them is what makes them special, the so called "Blockchain". Bitcoin might die, we will never know, but Blockchain is the real innovation. Distributed ledger technology can even be replicated in different businesses, from a supermarket to wall street. The key feature in Blockchain is that it is an open source technology were everyone can contribute to it. That's why we start seeing different types of blockchains, like the one for Bitcoin and the one for Ethereum. Those two are Permissonless ledgers in that anyone can participate in it, while there are other types of Blockchains like Sawtooth, Quorum, Fabric, Iroha, were the members must be authorized to be able to join the Blockchain. Those are called Permissoned ledgers.
As we can see, Bitcoin started the innovation revolution regarding Distributed Ledger Technologies. Since then, many different approached started to emerge.