This type of article does little to assist the education and understanding of NZ Super.
Crisis rhetoric, use of sums to confuse and camouflage, very little policy comment, nil comparative analysis, and no viable alternative schemes suggested .
One expects better from Shamubeel Eaqub who is quoted and utilized by Damien within the article , a lazy piece of work!
The question is asked ” that we could, in theory, continue to cover this cost, but something will have to give”?.
The answer is don’t play with good public policy. Yes review and or rewrite/remove the many poor examples of bad policy or poorly written legislation, eg Resource Management Act, or the complicated and poorly designed Three Waters scheme, but don’t fiddle with proven and simple public policy !
Kaspanz position is we must cover NZ SUPER cost, because of the reasons below, its great we have a scheme in place which is so balanced and profound, sing its praises, pay the cost, and look for savings elsewhere
NZ Superannuation is top quality public policy. No alternatives match that measure.. It is one of the worlds simplest retirement income systems, Every NZ resident is entitled to NZS from 65 as long as they meet residential criteria. It provides 66% of the national average wage for a married couple and about 50% for a single person living alone. It is adjusted annually to reflect changes in inflation, with a formula link to the national average wage. It is taxed as income. 
It is one of the cheapest schemes in the OECD, many countries paying far more in GDP,
As Susan St John and Clare Dale in their 2016 paper said “The projected NZS expenditure appears modest, especially if net rather than gross spending is counted, and when compared to current pension spending in other countries.” As Michael Little wood NZ foremost research commentator on NZ Super in a 2013 paper said “New Zealand Superannuation (NZS) is one of the simplest, most effective, and most cost-effective Tier 1 schemes in the developed world. We mess with it at our peril”
it is affordable for generations to come, and its the gold plated cushion for all, re planning and assumptions as one moves into retirement years living and associated options.