What's wrong is that millions and millions of German alpha males died in battle without reproducing, leaving a generation of wwak beta cucks in their wake. The same affliction is taking down many European countries, but Germany is the poster child because they took a worse drubbing than their neighbors. Half of her male population were casualties in ww2. Among young men, the percentage is even higher. If you watch footage of combat on the eastern front, 6 or 7 out of every ten of the young soldiers you see were most likely killed or wounded.
That's a difficult situation for any country to survive.
You can go to You Tube and see dozens of videos of entire divisions of Germans men, a lot of them teenage boys giving themselves up. So they didn’t all die off. They became generations of limp wristed socialist weenies.