Let's be clear - Apple Pay only works in North America and the UK. It's not just "a few Australians" that can't use it, it's the majority of the world that can't use it.
So again, logically, it makes no sense to have space taken up in a phone with a feature that the majority of users can't/don't use, and have another highly used feature removed in the name of "innovation".
Of course Apple would never remove NFC, and I'm not suggesting they do. I'm simply pointing out that impacting a huge percentage of customers by removing a highly popular function of the device, makes no logical sense.
A guiding principal of "Let's inconvenience the majority of our iPhone customers to save some device space" just seems absurd to me.
If you currently only use Wireless Headphones, this doesn't even impact you, yet it's entertaining to see how passionately you defend the decision, which is still only rumoured at this point.
You know hypothetically, I do wonder what a company like Apple would do, if Audtralian banks, banned Pay, and passed a law requiring all mobile devices to have a 3.5mm Jack. Similarly to the EU requiring all devices to have micro USB connectors for charging (of course Apple just skirted the issue by offering a lightning to USB adapter, so let's say Australian rules are tougher).
So would Apple in order to serve several million customers, offer a redesigned phone just for Australia, or pull out of the market? Interesting deilemma.
But let's look at your main point --
Apple has always removed something many people were using in the name of "innovation". SCSI, serial, VGA, Floppy drives, CD Roms, Ethernet, 30-pin dock, USB-A. And they didn't always replace it with something comperbale.
And everytime they did it, the market was not ready. Products for the new standard weren't available, if they were they were expensive and limited in function, they were buggy, and overly complex, often incompatible with the standard, or able to offer comperbale performance.
In the end, your main argument boils down to, this is something that impacts you, but not me. But a few years ago when Apple dropped Ethernet on their MacBook Pros, I was in exactly the same boat. In fact I still am, but life goes on with my daily use of Apple's Ethernet adapter. Moreover, your argument is that the decision to remove the 3.5mm Jack will inconvenience the majority of their customers based on the fact this directly affects you, and I'm not sure about that. It's hard for me to believe that Apple would make a major move like this without being at the "tipping point" for this inevitable transition to wireless, nor that they don't have the research to show it will not affect a "majority" of their customers. They're progressive, but so far anyway, I don't think they're crazy (despite their previous marketing campaign).