Don't be too quick to blame the Australian govt for this one, this is another case of malicious compliance from Valve - they want that outcome, as is clear in their Steam Support response screenshots going around that shift the blame entirely to the 'Australian govt eSafety codes'.

What they ignore is that by doing this, Steam is in breech of the codes that they're supposedly doing it to comply with. So.. I guess the ACCC will have to take Valve to court again.

The code terms mandate that age checks must be 'robust, reliable and fair'. Forcing people to get credit card accounts would not meet the code. It explicitly states "in order for age checks to be fair, service providers should offer more than one method of age checks to users".

This isn't a 'teething issue' either, Valve implemented the same user-hostile credit-card-only policy in the UK a year ago when the UK govt passed a similar law. Valve is still fighting compliance there too.