Here's the thing... If the person's phone has a data connection - the web page can just send the geolocation directly back to the emergency services! No need to get a human to read it out, then another human to listen and type it in to a different system.

Well, but then you need a special webpage made by the emergency services. They didn't have that; they just had what3words. You don't get to disparage things that exist in favour of things that don't exist.

You could of course try to build that page for emergency services, sell it to them, and have them maintain it. Or, you know, the dispatcher could just tell the person to open what3words...