EVM based deterministic execution has proven to be a resilient model for smart contracts. The other major inventions are not Ethereum itself, but it led to, to name a few, PoS consensus and zero knowledge proofs which I particularly admired. It has grown into a huge ecosystem of practical cryptographic schemes. Ponzi schemes are possible with just Bitcoin, and yeah Ethereum is full of crypto ponzis at the moment, but all these useful cryptographic inventions may not have been made practical without Ethereum.