This effect is certainly real, likely even the default, but it's not inevitable.
I had great results using AI to help my son study for his final exams in chemistry and math. We went through the review guide the teacher provided, he did the problems, I checked them, and I had Claude generate additional targeted problems as permutations of the ones he had difficulty with. He worked them and got more practice in exactly the areas he was weak.
I could have set these problems up myself, but it was much smoother to have Claude set them up and I validate them. It let him get a lot more reps in, in exactly the areas he _needed_ more practice, than he would have otherwise.
The key is that to learn you have to do the work. AI can help you figure out where you're weak and provide the wherewithal to get additional practice, and there's huge value there. But you have to lift the mental weights yourself.