Note that it's not like other countries don't have consumer protection agencies - the US FTC also engages in a lot of litigation. I'd love to see a comparison of the effectiveness of various countries' consumer protection authorities.
The terms “fit for purpose” and “reasonable reliability” give the ACCC a lot of latitude. Most things come with a 12 month warranty at a minimum as a result, and the retailer has to handle it which prevents them pawning you off to the manufacturer and also means warranty replacements are brand new instead of factory refurbs.
One notable example of this is that all mobile phones carry a 2 year warranty because phone plan contracts that include them are typically that long so that’s clearly the lower bound on their reasonable life span.
When I bought a pair of jeans in the US and the crotch blew out within a month I got blank stares when I went back to the store to ask for a refund. I got a refund after much loud complaining but if they hadn’t given in my options for pursuing further are limited and vary greatly from state to state.
In Australia if I was refused a refund in a similar situation I would just have to submit a complaint against them online (via the department of Fair Trading) outlining what my issue is, what I want the retailer to do, and what they said when I asked them. Fair trading then sends them a letter that strongly encourages them to self-mediate with the customer. This almost always works. If it doesn’t then it goes to small claims court where you don’t need a lawyer at all and where the consumer wins the majority of the time.
I would be willing to bet that there are a mere handful of countries (if any) with stronger nationwide consumer protection laws than Australia.
The process you describe for getting a refund in Australia sounds completely identical to my experience dealing with my state attorney general. The concepts of Implied Warranties of Merchantability and Fitness for a Particular Purpose are also widely recognized in the US -- at the state level.