Once one understands that Spaced repetition memory systems make memory a choice and that Learning increasingly complex ideas may amount to forming larger effective chunk sizes, it’s awfully tempting to gobble up new knowledge by downloading others’ decks of Spaced repetition memory system prompts. But assuming you’ve never studied it before, you’re much better off reading a textbook chapter on cell biology than you would be memorizing someone else’s deck: you must Learn before you memorize. Separately, Spaced repetition memory prompts alone are a poor communications medium; you still need the textbook’s narrative to ground the material.
It also happens that most downloadable SRS decks are badly made: Writing good spaced repetition memory prompts is hard.
See also: the Mnemonic medium, which tries to solve this problem.
Part of what’s going on here is likely the Generation effect. See e.g. Pan, S. C., Zung, I., Imundo, M. N., Zhang, X., & Qiu, Y. (2022). User-generated digital flashcards yield better learning than pre-made flashcards, which finds benefits of d=0.45 and d=0.29 for self-authored definition and application questions.