Well Denis White, you make a point where a small area like your home having multiple W3W's. I would suggest to choose the one by your door or driveway and stick with it. You happen to live in a wonderful 81m2 home (9 3x3m tiles, you mention), but how many people in the whole world have this opportunity? not many. This is where W3W becomes useful, the idea behind it is quite revolutionary: it is easy to communicate, it is not tied to a postal address, it can be used anywhere in the world in any language.
For example, emergency responders in Miami can get to the precise location easily, for example a heart attack in a golf course. You can say I'm at dog.pepper.box instead of Miami municipal golf course, hole 7, right about the second sand trap on the left Community Weekly Discussion: Mapping uncharted areas for emergency responders
One clear business case is the Mongolian post using it as their national addressing system. Partner: Mongolian Post adopts what3words as national addressing system | what3words where postal addresses are unreliable or non-existent. You can translate a W3W into a coordiante in WGS84 and do all sorts of calculations (and contextualize it). And the fact that the words are not related to to its neighbors make sense as it creates a unique point in the globe without any error.
Saying that I live in (19.448909, -99.216400) says nothing, as well as trace.reclaim.workshop does not. It is the use and context you give this information that is really useful: Rodolfo Gaona st #50, Lomas de Sotelo Neighborhood, Mexico City, Mexico. Which in order to do any sort of calculations as you mention I would need to convert it to am X,Y point in a map...
Cheers!
PS. dog.pepper.box does not exist, and the system can make corrections automatically: