> Why should we aspire to this? Why is NZs solution better
Because New Zealanders, as well as almost everyone else in a developed country, spend much less time and money on a chore that can be optimised to be easy and free? Not to mention the pure PR side of things - people don't like doing their taxes. The easier it is for them, the less they'll hate it.
The US has vastly more resources to draw on than NZ, and benefits from economies of scale.
The goal is constant improvement, not just making excuses for why the status quo has so many things broken or done very badly.
Aim higher.