It's far easier to have a successful seal on a remote island than the Czech Republic or Alabama. Land borders are both more secure and more porous than you'd think.
Also our politicians are deeply incompetent and were the only ones in Europe (AFAIK) aiming for herd immunity right off the bat, until they eventually ran the numbers on death rates if the ICUs ran out of capacity and realised it was a terrible idea.
As modest as the NZ economy is it's still a hub for a few industries, and people still wanted to come for business purposes.
2. Is your implication that the UK is so close to the mainland that the covid numbers are high due to people coming over in rafts? In that case the UK should have lower covid numbers because it has a much larger navy covering a the english channel, irish sea, and the north sea. Where as NZ has to cover the entire south pacific.
2. My point is that there's way more people entering, leaving, and going from A to B for whatever reason. Not trying to judge people, just stating a fact here.