Except that w3w is never going to replace those 5, so if it keeps spreading, we'll have a sixth not-trivially-compatible way. I'm reminded of https://xkcd.com/927/Considering there are two main ways of describing a grid reference in this country and 3+ ways of doing the same with lat and long, anything that makes it easier for the public to locate themselves is a good thing IMO.
Maybe it can, but it often doesn't. Over on another forum where it was being promoted recently, one of its gullible marks proudly claimed to be stood in some remote field far from the building where they were. I don't think we ever worked out whether it was another case of singular/plural confusion, homophones or the app misfiring. ETA: while some of us might have some idea that an app is putting out nonsense if it's not near 52,0 or starting 9F42 (for my home area), no-one can tell if a w3w is wildly wrong just by looking at it.What3words can give an accurate location to the size of a room in a house (3x3m) quite simply and accurately.
Why's that the comparison, rather than long press on a phone map and "share my location"?For the vast majority of the great unwashed who only have a phone to give them any idea of where they might be, then IMO it is a great asset. Compare this against a rambler derived OS grid ref which will be a accurate to a 100x100 square, assuming you have a map, romer to hand and a clue about what you're doing.
How is the 3m w3w grid more accurate than the sub-10cm one used in most geo: links?We're seeing far more instances of locations being given via 3 words and it's quicker and far more accurate and means we're wasting time not going inspect things only to find we've been given duff info. If lives were at stake then I can see why the emergency services are championing it
Also, I can give location of a defect in three different ways (street address, road number and offset, and geo: lat/long) along with GPS-tagged photos and still have workers waste my time claiming they couldn't find a 6m x 2m hole in the road. I doubt having another format to misuse will stop inspectors claiming submitted info is duff.
And if lives are ever at stake, I doubt it'll be w3w's bosses's lives.