Impatience is a design constraint
Callers compare you to whoever answered last, not to the answering service you had in 2018. If the first experience is a ring with no pickup, the rest of your service never starts. Strategy has to include the minute the phone rings, not only the visit after they arrive.
That does not mean every company needs a larger call center. It means the first response should be immediate, specific, and able to reach a human without a maze.
Where AI fits the strategy
Use it to remove the wait on the known questions, to qualify what the person needs, and to deliver a message or a transfer while the caller is still on the line. Use people for the moments that create loyalty or risk. One tool can sit in front of the phone, the message, and the handoff so the business is not assembling that path out of five products and a hope.
The offices that feel calm are not the ones that never get busy. They are the ones that decided, in advance, what the phone is allowed to say.