If you keep going down the page, you get actual narratives about the problems. For Australia, for instance, Australia Post has closed the office that handles incoming mail. New Zealand is more vague, but is basically turning down mail processing due to COVID restrictions.
USPS implies it is because of COVID restrictions. NZ Post is accepting mail, but there is a shipping capacity crunch and very little air cargo capacity.
Another way to look at it is USPS did not anticipate a crunch by buying capacity in advance.
NZ Post allows us to ship packages from the US to a US warehouse which then ship to NZ. This is still operating with delays. Amazon seems fine with deliveries not being delayed at this point.
International AirMail mostly travels in the holds of international passenger planes - those are just not flying - package deliver to NZ (DHL/Fedex/UPS) is mostly OK, but plain old mail, not so much
I count four widebodies between Auckland and California (LAX/SFO) in the air just as a random check on FR24 as I write this, so there's certainly capacity for some mail if USPS want to buy it.
AusPost has a similar service which I've found to be basically useless since most of the packages I want to use it for don't come from a retailer and instead are sent by family.
The cost of living here is very high. Goods, especially electronics, cost a lot more than the USA. Electronics costing 50% more here than in the USA is common.
I disagree with the comment left by lostlogin, I have found most products on Amazon ship to New Zealand, including products sold by third parties, though I would agree fewer independent stores are shipping to New Zealand. I think this is partly due to prices increases from the likes of Fedex and USPS.
Amazon Australia ships to NZ but the product selection is very poor.
Amazon just isn’t that good here. The shipping is either impossible and requires you to use a third party service which gives you a US postal address, or shipping is outrageously expensive.
It’s one of the things that happens when you live too far away I guess.
Last few orders I made was something like 8.99 for some random shoebox size of items (worth maybe 50-100 usd). So basically far from expensive. NZ local shipping is probably half that price.
The asterisks for Australia and New Zealand indicate that mail sent using "Priority Mail Express International" (the service that essentially the entire rest of the world outside the US calls "EMS") is still going through. If anyone really needs to get something from the US to those two countries, at least it's an option, and IMO it's much more reliable than typical mail.