For this part I think the more important thing is that schools and doctors usually use very out-dated ways for appointments, either by in-person, or by phone calls. Most of them don't even accept emails. Even if you can program something that speak the line for you through phone (shouldn't be crazily difficult), they won't be as intelligent as real secretaries who can take questions, do negotiaons, etc.
However if they accept emails the functionality shouldn't be too difficult, from the technical perspective.
TBH I think most of the inefficiency of our daily life is due to lack of use of modern technology in banking/schools/doctors/gov/etc. They always argue "oh but it's not safe".
I suspect the limitations around digit assistants are due to a lack of an entity graph, and not the ability to communicate.
For instance my doctor allows for bookings via App, and phone. Furthermore, my digital assistants know who my doctor is, but don’t know who my son’s doctor and teacher is.
However if they accept emails the functionality shouldn't be too difficult, from the technical perspective.
TBH I think most of the inefficiency of our daily life is due to lack of use of modern technology in banking/schools/doctors/gov/etc. They always argue "oh but it's not safe".