Passkeys instead of seed phrases
The seed phrase is the single biggest reason ordinary people abandon crypto wallets. Account abstraction lets you delete it entirely.
Ask someone who has never used a wallet to write twelve words on paper and keep them safe forever, and you have lost most of them at that screen. It is the clearest example in software of an implementation detail escaping into the user experience.
ERC-4337 changes what is possible because the account becomes a contract rather than a keypair. Authorisation is a rule the contract enforces, which means the signing key can be a passkey held in the device's secure enclave and never leave it.
That removes the phrase but creates a new question: what happens when the phone is lost. The answer is recovery designed deliberately — guardians who can jointly authorise a key rotation, behind a timelock with an on-chain cancellation window so a compromised guardian cannot act quickly.
The second thing worth deleting is gas. A user who must acquire one token before they can move another has been handed the protocol's problem. A paymaster sponsors the fee and the user transacts in a stablecoin they already understand.
The trade is that you have moved risk from the user's paper backup into your contract logic, which is a far less forgiving place for a bug. Everything here has to be written invariant-first and audited properly. Convenience that loses funds is worse than the seed phrase was.