If you are looking for a "review" of the experience of keeping one, here is why experts and conservationists say they would make poor domestic companions: The "Ownership" Reality

Kiwi are flightless, nocturnal birds native only to New Zealand. They have the second largest egg per body weight of any bird. National Zoo Facts and threats to kiwi - Department of Conservation

A kiwi can live between 25 and 50 years , representing a massive, multi-decade commitment that is currently impossible for a private citizen to fulfill. How to "Support" Instead

They require large amounts of space to roam and a specific diet of soil invertebrates (like worms and grubs), making them incredibly difficult to maintain in a home setting.

Since you can't buy one, you can "adopt" or support them through official conservation channels:

Places like Willowbank Wildlife Reserve or the National Kiwi Hatchery in New Zealand allow you to see them in controlled, ethical environments. North Island brown kiwi - National Zoo