That does not solve exchange take over and transaction reversibility/clawback until the settlement X days in the future which is basic tenet of risk mitigation.
The reason you cannot electronically rob Ameritrade is because NOTHING can be done immediately outside Ameritrade. Since the settlement is at least T+3 there's no such thing as "Obtain control in 30 seconds and be out of there 3 minutes later with the loot"
Delay for risk mitigation on exchanges are known. You transaction will settle on a 3rd business day.
After a wire is authorized by a broker (i.e. passed authentication and the person making a request is authorized to make it and the margin is satisfied and there's no block on the fed level), it will be posted by your bank on the same fed business day if the wire is authorized before fed cut off time.
Coinbase is a VC-funded shady co if it does not operate based on strict and known confines. Banks and brokers spell out the confines (new account rules/withdrawal rules/funds availability rules) at the opening of a new account.
The reason you cannot electronically rob Ameritrade is because NOTHING can be done immediately outside Ameritrade. Since the settlement is at least T+3 there's no such thing as "Obtain control in 30 seconds and be out of there 3 minutes later with the loot"