Spain invested on a standard infrastructure (client-side certificates) back in the days (early 2000 ?) and I am amazed by how simple, how well it works and how

Spain invested on a standard infrastructure (client-side certificates) back in the days (early 2000 ?) and I am amazed by how simple, how well it works and how nobody else has thought about doing the same anywhere else (to my knowledge). Well done Spain, at least on this.