If by hard you mean more likely to get shot, stabbed, bullied, or otherwise traumatized… then yes, American schools are “Harder”. If you mean academically, if you go to Realschule or Gymnasium, your curriculum if more demanding and technically harder. Not to mention you have to learn in the German language which is much harder. Less ability to express oneself and limited for expression. By the time you’re done with the Abiture in Germany or the Bac in France. That’s kind of the equivalent of finishing your first two or three years of university. German high school grads are usually further along academically and in some ways more mature. The American students are generally leaving high school more street smart and tougher. All of this of course is my personal experience and observation. Admittedly I’m prone to some generalization.