In every business there is one person who knows where everything is. The client history, the supplier disputes, the contract clauses, the email from two years ago that suddenly matters today. Lose that person for a week and the business slows down.
The Useful Employee is exactly that person. Ask it anything about your business and you get the answer in ten seconds. Email, voice note, Slack, or its own interface.
It does not get sick. It does not forget. And it does not quit.