Call routing has historically meant "press 1 for English." The modern version routes by understanding the caller's actual intent in their own words, looking up their record in the CRM, and applying real-world rules (route VIP customers to a senior writer, route new-patient calls to the front desk lead, route after-hours emergencies to the on-call).
An AI agent does this without an IVR menu. It listens to the first sentence, identifies the caller and the intent, and either resolves the call directly or transfers to the right human queue.
The metric to watch is misrouting rate: how often a call ends up in the wrong queue. A useful vendor reports this, ideally per routing decision, and surfaces the misroutes in your CRM so you can correct the underlying rule.