At least New Zealand is on the map.

I don't think we're unique in the world, this impacts most countries but I believe the average kiwi doesn't realize how bad it is and so thinks NZ is still a fair-go country.

Caused by dozens of issues over the past 50+ years:

• No1 on my list would be the demonization of unions (deserved in some cases, probably not in most), leading to reduced membership and weakened labour bargaining power
• Gradually shifting tax burden from those who could afford it (thus redistributing some of that wealth into public assets) and onto the lower-earning masses who can't. By way of policy, tax rates, financial structure (trusts etc)
• Ongoing pro-business policy on the right with compromise worker/business friendly policy on the left
• Requiring business to prioritise profits for owners/investors, without employees having equal footing in this consideration.
• Anti competitive/duopoly businesses in almost every major sector
• All of the above leading to wage suppression
• Nepotism and racism leading to those who go to private schools more likely to land lucrative roles
• Privatisation of national assets. Sold to only those that can afford to invest (amplifying inequality) then once there is a profit incentive, only increases the costs for consumers.
• Govt getting lumped with cleaning up the carcass after private business has bled an asset dry to retain it for the national benefits or to avoid environmental damage (Kiwi Rail, Marsden point)
• Demonization of welfare meaning anyone hitting bottom just gets pushed further into the dirt
• Demonization of any attempts at wealth distribution. CGT increasing the top brackets, UBI etc.
• Low productivity. Shitty businesses run by owners/managers who can't see past the end of their nose.
• Productivity improvements fought by the labour force because productively gains aren't shared (less jobs)
• NIMBYism
• Short term thinking by both Govt and voters. Often caused by immediate need as more and more people become desperate and in hardship.

Probably many, many more but in summing up, it's capitalism, it's nepotism and racism - it's the vibe.

Very interesting take, OP. Can you please elaborate why you think this is the situation for NZ?

This doesn't look like. If the top 1% is only 52 thousand people and the bottom 90% is 5.4 million people the areas don't look right.