The Doorman Fallacy is exactly this—thinking that one function of a job is the whole job. The doorman doesn't just open doors nor relay messages. They're eyes and ears, security, friendliness, an extra hand with bags, local knowledge, emergency response... The list goes on and on. Almost none of their functions can be replaced with an intercom.
The value of the doorman isn't the intercom functionality.
People like doorman buildings because the building has a real person with eyes on the premises at all times.
An intercom or automatic door opening system can't deal with delivery people who can't figure out the intercom system, don't follow delivery instructions, leave your package/food somewhere random, etc. And that's only a fraction of the value a doorman provides.
An intercom system won't deter trespassers, petty crime, etc.
As long as the building is large enough, the cost is negligible.
I randomly picked a listing in NYC, 219 East 69th Street. 145 apartments on 13 floors.
Let's say you're paying a doorman 24/7 at $30/hour, that's $150/month/resident.
I’m sure it’s similarly true for travel agents, real estate agents, probably lawyers, etc. Just because there are circumstances when someone values them doesn’t automatically justify them everywhere or refute that many of them basically don’t do anything.
Real estate agents are a good example. They might be the only people involved aware of the processes everyone's engaged in and moving things forward. Having helped build tools for a local shop I can tell you that their checklists and flowcharts can't and won't be built with AI because hoarding and sharing information has always been part of their competitive advantage.
A corollary might be that the value of human involvement is unknowable because human beings aren't rational. The Doorman is a buffer against chaos.
First they provide real security an intercom does not. They know everyone and won't let an unknown go through the door without checking in.
The courier leave their wares to them, and can hand over packages for the courier.
There's no extra cost, really, to having them do dry cleaning since all they do is hand over all the dry cleaning to a service that comes by.