Not every step needs it. A classification that files an email can run unattended. A refund, a contract clause or a message to a customer should wait for a person until the system has earned trust through measured accuracy.
The approval point is a design decision, not a fallback. It is what lets a business adopt AI on real work without handing it the authority to do damage.
The approval queue is also where the training data for improving the system comes from: every correction a person makes is a labelled example.