Ethereum, often referred to as the second-largest cryptocurrency by market capitalization, is more than just a digital currency. Utilizing blockchain technology, Ethereum supports a decentralized platform that enables developers to build and deploy smart contracts and decentralized applications (DApps). This functionality has made Ethereum the backbone of a significant portion of the decentralized finance (DeFi) ecosystem. As you explore Ethereum, it's essential to understand both its remarkable potential, such as facilitating programmable money and enhancing transaction transparency, and its risks, including security vulnerabilities and scalability challenges that can arise as more users flock to the platform.

Despite its revolutionary aspects, Ethereum does grapple with some inherent pitfalls. One of the primary concerns is the scalability problems that can lead to network congestion and high gas fees, particularly during peak usage times. Moreover, smart contracts, while powerful, are not immune to bugs or errors, as seen in infamous hacks like the DAO incident. As Ethereum progresses towards its transition to Ethereum 2.0, understanding these complexities will be crucial for users and investors who wish to leverage its capabilities while remaining aware of the associated risks.

The sustainability of Ethereum (ETH) has become a pressing concern as the cryptocurrency landscape continues to evolve. With the transition to Ethereum 2.0 and the shift from a proof-of-work (PoW) to a proof-of-stake (PoS) consensus mechanism, ETH aims to significantly reduce its energy consumption by up to 99%. This change is pivotal not just for the environmental impact but also for enhancing scalability and transaction speeds. Critics often point to the high energy consumption of previous PoW systems, but the upcoming improvements indicate a more sustainable future for the platform.

Moreover, the long-term viability of ETH in the crypto market hinges not only on its energy sustainability but also on its adaptability as a platform for decentralized applications (dApps) and smart contracts. As more developers build on Ethereum, factors such as network usability and community support will play a crucial role in determining its dominance. In this rapidly changing landscape, those who invest in ETH must consider both technological advancements and the broader implications of sustainability within the crypto universe.

As the two leading cryptocurrencies, Ethereum and Bitcoin represent distinct blockchain technologies with different purposes and functionalities. Bitcoin, created in 2009, is primarily known as a digital currency designed for peer-to-peer transactions, serving as a store of value and a medium of exchange. In contrast, Ethereum, launched in 2015, goes beyond currency and introduces the concept of smart contracts, enabling decentralized applications (dApps) to run on its platform. This fundamental difference sparks an ongoing debate about which cryptocurrency will ultimately dominate the future of finance and technology. For more insights on Bitcoin's role as digital gold, you can read about it on Investopedia.

When considering the potential for future dominance, several factors come into play. Firstly, Ethereum's transition to a proof-of-stake (PoS) consensus mechanism is designed to improve scalability, security, and energy efficiency, positioning it as a strong contender in the crypto space. Conversely, Bitcoin remains the most recognized and widely adopted digital currency, with significant institutional backing. Factors influencing future performance include regulatory developments, market adoption, and technological advancements. A detailed analysis of Ethereum's roadmap and its implications for the future can be found on Coindesk.