The Nats & Labour cannot solve NZ's cost-of-living problems since both have rejected neoliberalism.
It pays to reflect on an interview PM Ardern gave to Stuff in 2017 (at that time she was opposition leader) which was titled "Ardern says neoliberalism has failed".
"The opposition leader, outlining her economic ideology to RNZ in a lengthy interview, was asked if she agreed with former National Party PM Jim Bolger's assessment of neoliberalism in NZ: that it had failed. "Yes," she replied.
Little could our PM have known that several years later, NZ would be buffeted by massive supply-side shocks which would lead to a sky-rocketing cost-of-living.
Now the "neoliberal" reforms of the 1980s were about designing ways to mitigate these kinds of shocks - they were reforms aimed at cutting costs & increasing productivity by promoting market-mechanisms to make the economy function more efficiently.
Since both National & Labour have thoroughly rejected such reforms, due to being mutually terrified that doing otherwise would lead to their brands becoming polluted by the label "neo-liberal", which they think doesn't play well with voters, I can't see how either party is remotely equipped to solve the cost-of-living issues engulfing us.