Arthur Breitman, co-founder of Tezos, believed hard forks — like that which created Ethereum Classic (ETC) — to be detrimental to a blockchain's utility. Tezos avoids such chain splits using an on-chain governance and self-amendment mechanism.
Another difference is the consensus mechanism used. Tezos's LPoS is more environmentally sound than Ethereum 1.0's proof-of-work. It allows for more widespread participation than Ethereum 2.0's proof-of-stake, since any XTZ holder can delegate to a baker.
Finally, Tezos's smart contract programming language, Michelson, allows developers to formally verify the mathematical assumptions of their smart contracts. This can help prevent costly bugs and vulnerabilities.