AI lets the agency better be able to afford to hire and keep the excellent humans around to solve complex problems. It's better than a human that also can't fix your issue themselves and has to ask you to transfer to the other person. Ideally, the AI agent would have let you book a callback time with the specific right human who's best able to fix your issue. Some companies are able to do this, and you, the customer, never realize that of the 100 specialists in the building, you got connected to the one person who understands your issue and has the tools to fix it.
Customer service is hard because it has to filter out 90% noise, 9% fairly straightforward tasks, and the <1% of complex issues that need to be sent to the right human.