@mtmail @jonty The key difference is that if the government pays to develop a fine-grained postal code system, albeit implemented by a privatised post office or, in the case of Ireland, by Capita, then there's usually some light at the end of the tunnel that the data might be made open on some way, medium term (cf. CodePoint Open). If you relinquish to W3W you are inextricably linked to a global-scale system run by a foreign company - until their patent runs out.
@mtmail @jonty Apparently, at least the following are in the W3W web:
Kiribati
Mongolia
Sint-Maarten
Côte d’Ivoire
Djibouti
Tonga
Nigeria
Solomon Islands
According to Wikipedia, W3W has been losing tens of millions every year.
Idea for philanthropist: buy them up, wind up the company and free the patent.