What is the driving force behind New Zealand's economy?

It's a country with a population of only about 3 million that doesn't seem to have any particular reason to be wealthy.
Aside from the fact that it seems unlikely to be invaded, its position for trade actually looks worse than Korea's.
In fact, back in 1999,
when Spain was at $14,100,
New Zealand was at $13,800,
which was slightly higher than Taiwan at $12,000 at the time,
and somewhat higher than Korea at $9,200.
As of 2025,
Korea is at $36,227,
Japan is at $35,985,
and New Zealand is at $48,126,
while Spain is at $38,648.
It has transformed into a quite prosperous country.
What is the driving force that has allowed it to become so much wealthier compared to the 90s and 00s?
Basically, excluding South Africa, it seems that most English-speaking countries are doing quite well.