Is this a paid ad on the BBC? If What3Words was an open database, it would be a decent system. But it's a proprietary database on top of GPS controlled by a company that aggressively uses the DMCA: https://en.wikipedia.org/wiki/What3words#Criticism
The BBC article doesn't explain why this is better than lat/lon other than a quote saying "I tried to get people to use longitude and latitude but that never caught on," by the company's founder.