I’ve heard from my gamer friends who reside in Australia that any game that’s 18+ on steam is hit with a barrier of AV (mainly adding a CC, not a debit card) before they can even view the page despite them owning the title. The real solution to overcome this hurdle is: region change, as from Australia > (other country) which is only applicable if you’re an expat gamer having a valid payment method & billing address from (that country).

spoiler

I obtained this screenshot from a friend of mine who lives in Australia, this came up for any "adult" (non-pornographic) game like Doom or Resident Evil. I can view those games as normal as someone from abroad.

The alternative is using a premium VPN for region change but you’ll still require both a valid payment method & billing address from abroad finalizing steam “migration” to another nation’s storefront. However, this carries its own risks relating to account termination if caught. I’m a foreigner, so it doesn’t affect me personally but I feel them, the frustrations on having to submit CC just to gain access otherwise the page is inaccessible.