Why do you use ETH as the base token?
The main reason is that it allows 100% compatibility between contracts deployed in Ethereum and Aurora. There is no need to change anything if you deploy a contract on Aurora. The token you'll use for billing will also be ETH ― currency that is already so common and popular.
We aim to work together and facilitate the process. We want to extend the use case of ETH, we want to scale the Ethereum network rather than compete with it.
We strive to give a chance to the Ethereum community to grow and extend outside of the Ethereum blockchain.