A model can answer questions. An agent can finish the work.
Business does not pay for well-written text. It pays for completed work: a contract reviewed against policy, an invoice reconciled and ready for posting, a disputed case delivered to the right person with the justification already attached.
A model saves time on a single request. An agent removes manual work from the flow: for example, 25,000 documents a month can pass with almost no human involvement, and people handle only the exceptions.
Only an agent can be allowed into systems of record. It has rights, limits, an audit trail and a human who confirms irreversible actions. A model stays in the chat; an agent enters the process.