Ethereum and Bitcoin are both cryptocurrencies but they serve a very different function.
Ethereum is a blockchain that allows smart contracts and the building of decentralized applications upon its blockchain.
Bitcoin, on the other hand, is a peer to peer technology and to be used as a form of digital currency. Sort of like a paper note just that it is being stored in a Hot wallet or Hardware wallet on your phone or on a device.
Essentially the price of Ethereum is based on its technology and purpose of allowing smart contracts and applications to be built on it, whereby Bitcoin is used to make purchases.