The Swiss one was codified as an international standard as IEC 60906-1, which South Africa and Brazil have adopted, so it should be the de facto option for any

The Swiss one was codified as an international standard as IEC 60906-1, which South Africa and Brazil have adopted, so it should be the de facto option for any country looking to replace their current system. The problem with replacing British plugs is that they need fuses because most British houses are wired with ring circuits, instead of radial circuits like the rest of the world. So I don't see them moving to a new standard any time soon.