An Evaluation of Location Encoding Systems (2018)
github.com
github.com
I am skeptical that all the considerations for the design are practical and that no business case benefitting Google was considered, seeing their track record on this. But so far I cannot find anything indicating that this is the case.
I do wish more projects would use plus codes more evidently. They are searchable in OSM, but do not display prominently when looking at a location. Even in Google Maps, it is hit or miss whether you'll get a plus code when viewing a location.
These are not a replacement for GPS coordinates, but they serve a good purpose. GPS coordinates mark a specific point on the earth's surface, whereas plus codes mark a place, irrespective of size and shape. They are both very useful and I think both should be universally adopted.
So there are two comparable projects, S2 library and ubers H3, both of them represent areas but the codes are not memorable. In each case, if you want to represent usefull area, say a park, you are going to have to combine multiple smaller cells to make up that shape. Thats not going to be memorable to a human. So i am not clear why a memorable system would ever need to represent an area.
Well, I have to switch from Google Maps to OSM every time I want a GPS coordinate. So yes, they are not used, but not because they are difficult to use per se, but because Google is pushing their own agenda on PlusCodes and passive-aggressively discourage GPS coordinates.
The plus code can be found as simply as scrolling down.