We build dolfyn, custom AI phone receptionists, and the assumption we run into most is that every AI receptionist is basically the same. In practice the gap is huge, and it comes down to how the call is actually handled.

Most tools are one generic bot reading a script you configure yourself. That falls apart on the calls that matter. Someone with a real emergency, like no heat in winter, needs a completely different conversation than someone asking about pricing, and a single bot trying to do everything tends to either interrogate people or miss the important part.