Hold is a decision to leave
People calling a local business are often in a car, on a job site, or between patients. A long hold is not neutral. They hang up and call the next number. Some leave a voicemail nobody will hear until tomorrow. Some do not call back.
There is no single number of seconds that fits every caller. What is consistent is the direction: patience is shorter than it was, and a missed first ring is more expensive than a polite answer.
Answer, then route
An AI receptionist removes the wait for the common path. The caller hears a greeting immediately, states the need, and either gets the fact or a transfer. If the person is busy, the agent says so and takes the message instead of looping hold music.
That is different from a phone tree. Press-1 menus make people wait and then guess. A voice agent can hear 'billing' or 'my child has a fever' and take the path you wrote for that request.