

Germany had this since forever, it’s just how offline laws translate to the internet: There’s a difference between a) ordinary nudity, b) eroticism and c) straight-up porn. The latter was always 18+, in video rental stores etc. they would have a separate section and if you didn’t look of age you’d get ID’d.
You can’t order alcohol online in Germany without a proper age check, and the same applies to porn. For paid offerings that’s no issue, payment providers offer age checks (your bank knows how old you are and them vouching suffices), for free sites it’s a no-go, noone is going to go through the hassle. Especially as you can escape off the German-language internet onto the international one and merely click through an “are you 18” banner.
Notably, pornhub isn’t blocked in Germany – neither from the German side, nor from pornhub’s. Very occasionally DNS bans are ordered when a site without age checks tries to specifically target the German market. Mostly though it’s down to German google not serving up those international porn sites which in the end is good enough for the youth protection authorities because the point is not to make access impossible, it’s to make sure that youth not ready for content doesn’t stumble across it. And once you’re actively seeking, you’re ready, the hoops you have to jump through are proof of the “active” part. YMMV on “not ready for porn with 18”, back in the days there was still softcore. On free TV. Probably won’t hurt kids to not start out with gonzo.
Let me throw a disgusted upvote in your general direction.