Australia has the longest one word name of any country in the British Commonwealth. This is a trivial matter but may explain why no other country ritually abbreviates as many words and peoples’ names as it can.
Start with Oz for Australia and Aussie for Australia, g’day, the adding of the letter ‘o’ after the final consonant of many names as in ‘g’day Gordo’ and you begin to get the idea. Then you have footy, roo, the splendid arvo for afternoon, cozzie for swimming costume, the excellent garbo for garbage collector and so it goes on. It ain’t pretty but it works for them.