Traditionally an account is just a key pair with fixed rules. Account abstraction lets the account define its own validation logic, which is what makes a smart-contract-wallet practical at scale.
Concrete benefits for traders: batch approve-and-swap into one signature, set per-session spending limits for a trading app, recover an account through designated guardians, and pay gas in a stablecoin via a paymaster.
The new risks are code risk in the wallet itself, dependence on bundler infrastructure that can censor or stall, and inconsistent support across chains. Test small before moving a treasury into one.
Related: smart-contract-wallet, gasless-transaction, gas-fee, multisig-wallet