There are legitimate concerns about security on Ethereum. With such a complex system, and so many different programs running on it, the attack surface is large. And given the challenges the community faces in migrating to Ethereum 2.0, including a new proof-of-stake consensus mechanism and a sharding solution for scaling transactions, it’s still not assured it will ever be ready for prime time.
Decentralizing Everything with Ethereum's Vitalik Buterin | Disrupt SF 2017
More importantly, though, the Bitcoin and Ethereum networks are different with respect to their overall aims. While bitcoin was created as an alternative to national currencies and thus aspires to be a medium of exchange and a store of value, Ethereum was intended as a platform to facilitate immutable, programmatic contracts, and applications via its own currency.
Like other blockchains, Ethereum has a native cryptocurrency called Ether (ETH). ETH is digital money. If you’ve heard of Bitcoin, ETH has many of the same features. It is purely digital, and can be sent to anyone anywhere in the world instantly. The supply of ETH isn’t controlled by any government or company – it is decentralized, and it is scarce. People all over the world use ETH to make payments, as a store of value, or as collateral. The latest news about Ethereum mostly concerns the move to Serenity the last post-development phase of Ethereum as well as changing Ether mining’s concept from Proof-of-Work to Proof-of-Stake in order to reduce the power cost of the process.