How hard is it for you to buy 18+ games? If it's not too much trouble, we can talk about it in private messages.
The thing is it is "just" a youth protection law and should not affect adults at all but the way Steam startet to handle it, all adults are affected by it as so to speak collateral damage.
If an adult game rates itself 18+ on steam we can access the store page at least trough a direct link and wishlist/buy the game normally.
It will still not show up by searching the shop though and the community page is still blocked with a german IP due to steam does not want to differ between adults an non adults.
Without a 18+ rating the store page is like the community page blocked.
This only applies to adult(porn, soft and hardcore) games on steam even if softcore porn is by default 16+ (softcore means no penetration) in germany. Every other game regardless its rating is not affected by it on steam.
For digital distribution of games the rating can be given by the maker itself.
When someone wants to distibute physical copys it would be different because then another paragraph of the youth protection law would apply.
As an german adult of 18+ you can by whatever you want game and movie wise there is no law that forbid us to do so.
If you want to discuss further leave me a private message.
I think anything furter would be to off topic. But everything said so far might be of interest for adult (porn) game developers to know.