Of course you don't have to create your own cards, but they would work better if you did. You can use ChatGPT to automate onerous tasks, but have to compensate for it by engaging with the material in other ways. I doubt that grinding decks is enough. Depends on the activity and the goal I guess. Acing exams, sure, without doubt.
A concept applies here where you really don't want to spend unbound time studying. It's a great way to burn out. "A" students, when interviewed, frequently reference doing "enough" and then stopping.
Optimizing your study time by taking the "boring" work, e.g. building flashcards of material you organized yourself, cuts down on time spent not doing work that's maximally effective (memorizing flashcards).
If a person had infinite time, making flashcards would be just one more thing on an unbound list of things they could do to learn the material better. But people don't have infinite time, and considering you're already "familiar" with the material since you wrote and organized it, building flashcards is something you can't really afford to spend time on.
When I went back to school to get my undergrad, I focused on optimizing my time, because procrastination was a huge problem for me the first time around. Being efficient and not spending a single second longer than I have to in order to get an "A" is important to me, and using ChatGPT to help me with that has been wildly successful so far.
