28 years old is when we stop growing, this having our body changing. We get fat from the now useless calories which until then helped us grow, at least no strong hormonal process dictates our fears of change. Most of us are now responsible parents and have had a job enough year to actually accept responsibilities. Some even were successful enough to start a proper business. These people don’t base their voting upon political flattery or media emotional soup but rather according to their experience as adults.
I cannot believe NZ wants 16 yo to vote. Would you trust a huge chunk of immatures who trust Greta Thunberg to decide for you?
Sorry (I am not), I had to get this out.
An age limit is actually a very poor criteria.
Something close to Heinlein's "Starship Troopers" is a better place to START.
IMO...
We need "fewer" voters, and more people "counted".
For example:
The married/legal head of the household should be the voter. BUT, that voter gets to count everyone in the household that they are RESPONSIBLE for. This way, wives and children and elderly and live in relatives are ALL COUNTED - BUT, they don't vote counter to the person that is doing the reality of the heavy lifting in that house. Throw in some property ownership criteria or military service like Heinlein and we would have a MUCH better system than universal sufferage.
Just an example...