Why wait 7 days to claim funds when bridge to Ethereum?

Whenever there are bridge transactions into the Ethereum mainnet using the official Arbitrum bridge, there is a mandatory 7-day waiting period for withdrawals and this is due to the bridge's security measures.

The 7-day waiting period for withdrawals back to L1 (mainnet) on Arbitrum is a security measure designed to protect against fraud. This is because Arbitrum is an optimistic rollup, which means that transactions are initially processed without being verified. If someone tries to submit a fraudulent transaction, there is a 7-day window during which verifiers can submit a fraud proof. If a fraud proof is submitted, the transaction will be reversed and the fraudster will be penalized.