The main problem with geoblocking like this is that it stops me (in Australia) using Amazon (in the USA) to buy stuff to send to a recipient in the USA.
I have family in the USA (and also other not-Australia countries too), and every Christmas or birthday I buy some tat on Amazon and have it shipped directly to my niece(s) and/or or nephew(s). That's *much* faster than shipping from Australia. And it's *much* cheaper too.
I'm sure this is a very common scenario.
With geoblocking, they simply won't take my money, so I'm forced to use some other web site.
Amazon - you're shooting yourself in the foot with this.