Re: IQ downward spiral...
Rubbish. They closed the border a bit late, but started contact tracing from the very first case, and imposed distancing measures in good time. 100% is due to the excellent, coordinated, well communicated government response. No country has done better. Kudos to the government. Even their right wing opponents know that they did almost everything right.
Of course, having no land borders made it easier. But thousands of people arrive by air every day in normal times.