Anki became useful for me after I stopped making flashcards on the run, while I was learning the content. Now I make flashcards only from what I already know from memory, two or three days after I've learned it through other methods, without ever reading anything while I'm typing into a text file that I'll then import to Anki ( their GUI is too slow and cumbersome for me ).

Spaced repetition came out of scientific studies on the forgetting curve; these weren't studies on the learning curve.