My 2c as a infrequent flier.
AirNZ too hard as you found out to get status. I am with Asiana Club and I visit mostly Asia while not really with Asiana but I can still credit points to them instead. Asiana flies to Oz but not NZ. So I chose it over Aegean which is another *A that is easier to get status than AirNZ. Easier with rewards too but it''s not APD which is equiv to a dollar ie if you have the points you can book a Christmas fare. With Asiana I guess when I inter Asia I can use them.
But practically I haven't earnt much b/c I can fly when I want. With AirNZ grabaseats they don't earn points anyway so no point using my Asiana Card. Maybe when I need to fly with decent priced fares then I can use it. So for now I pretty much just earn APD with my credit card and get a freebie going to AKL for my intl flight. I cannot get status anyway, so no point in trying but anyway the GlobalPlus Gold credit card doesn't provide any status points anymore, not that it matters to me anyway .... A AirNZ grabaseat to Japan saving $1200 in instant cash is better than paying $2,000 for the same fare just to get points but I think I need 25 or such return trips to get back $2,000 APD. So on this note, any other FFP is better than AirNZ. Well I don't fly Prem Economy plus.
My mum flies to Canada to see her mum. So I put her on Aeroplan Club. She's not even on AirNZ programme. Well she doesn't put much on the CC and she gets a superannuation plan 50% discount on her ANZ Platinum Cashback card at a 1% cashback rate. So she uses that instead of the ANZ Plat AirNZ card which doesn't offer the 50% discount which earns a bit more than 1% ie $90 = 1APD.