Solana's key difference with Ethereum is that it solves the scaling on layer 1 - instead of other workaround solutions. Solana was designed to be fast by improving network speed and communication between nodes. One key advantage of scaling in this manner is that it doesn't break composability - the communication between different smart contracts. Ethereum 2.0 scales using "shards" - a technique that could potentially introduce communication issues between decentralized applications on different shards.