The only way that makes any sense is to introduce means testing on all benefits, not just the ones for poor people.
It does make sense. If we reduce the retirement age to say 63 for a defined period it allows access to Kiwisaver and allows seniors to retire and leave the work force thus helping ease unemployment, This in turn can reduce dependency on job seeker benefits.
You're adding more cost on the state while largely getting poor people to pay for it.
A fair proportion of old age beneficiaries don't need their benefits. If they are treated the same as any other beneficiary then I can see some logic.