Running a small website with a calendar booking link just sounds much easier, cheaper, less error prone, and a better UX than running a voice LLM that is connected to a RAG and calendar. And I still don't think the technology around us has been built to support small websites or small businesses.
If the LLM augmented voicemail is not much more than the business voicemail service that such places have now, is it enough value add?
That also implies other things - such as the capability to integrate with the calendar and appointment system which I'm still in the very hesitant side, but it could be an interesting service add on if it was properly limited.