One consideration here that many folks (US in particular) may not consider is that smokers put a very substantial burden on the NZ healthcare system which is taxpayer funded.
Of course, there are plenty of counter examples to this such as obesity (NZ is #2 in obesity only to US at #1) where the costs don’t result in any substantial regulation or prohibition. Alcohol is a ginormous topic too, NZ has an extremely unhealthy relationship with it.
I think I agree that the stripping of liberties is uncomfortable, even if I’m totally opposed to smoking.