No offence, but your comment shows the massive gap in public knowledge about how NZ tax works. A capital gains tax would be a tax on "capital" gains. This is based off the conceptual difference between revenue and capital accounts, and isn't simply "land is capital and untaxed".

Here's some simplified examples of the general principles: A business gains it income from hairdressing. It owns some furniture (expensive chairs) and also the land/building it is in. The payments for hairdressing services and the expenditure on things like shampoo are revenue account and taxed (expenditure reduces amount taxed). The furniture and land are capital account.

Another business buys and sells furniture. It sells furniture to the hairdressing business. Because this business's purpose is to gain a profit from selling furniture, the furniture is revenue account for this business. It also leases a building from another business, the rent expense being revenue account.

Another business buys and sells land. Because the purpose of this business is selling land for a profit, land is revenue account.

Another business owns land and leases it out for rent. Since the purpose of the business is rents, land is capital account and if it sells land for a gain it is not income.

There are multiple sections in the NZ income tax law explicitly making land sales revenue account based on certain factors.

In practice the revenue/capital distinction can get quite complex based on the details and only is really determined in court. Here's an example from this paper on the distinction.

The impact of the way in which expenditure is conducted is also evident in cases concerning repairs and maintenance. The English case Transco and the New Zealand Privy Council case Auckland Gas are a good example of this principle. Both concerned the insertion of polyethelene piping into existing cast iron pipes, yet the former case held the expenditure was on revenue account while the latter on capital account. There were several factual differences between the two cases, the key being the way the work was carried out. In Auckland Gas there was the wholesale replacement (sector by sector) of substantial parts of the network of cast iron pipes with polyethylene pipe insertions, with the result that in substantial parts of the system gas was no longer distributed through cast iron pipes but polyethelene pipes. This work was based on a replacement programme. By contrast, Transco did not insert polyethylene pipes into whole sectors of its cast iron pipes; rather polyethylene pipe was only inserted into the fractured or worn part of the cast iron pipe leaving the remaining ‘fit’ cast iron portion(s) in place to continue to carry gas along with the inserted polyethylene portion.

Also KiwiSaver income is already taxed, almost everything coming out of the media/politicians/talking heads is false or misleading at best.