“Steam started blocking Australian users from viewing or buying 18+ rated games on September 9, 2026, unless they attach a valid credit card to their account. Valve’s rollout affects hundreds of mature-rated titles, including Cyberpunk 2077 and Doom Eternal, and it doesn’t matter whether the account is brand new or fifteen years old with a library full of paid-for adult games. Without a credit card on file, those store pages, search results, and even home-page recommendations simply disappear.”
Valve’s justification for an exemption according to that letter I linked above was that Community Hub was an incidental side feature of Steam. Essentially the same argument that got GitHub an exemption. I even agree with them.
An overall age verification strategy for all online content would answer the question though.
I’ve come at the situation in the context of the social media changes, because that’s what Valve cited in their letter.