This has been my experience as well (especially with Anki), though I've always felt like my ability to memorize information to be poor in general. In my experience, I find it easier to memorize things rather through brute force/frequent repetition. To use memorizing foreign language vocabulary as an example; repeating words to myself, listening, or writing them out for 30-60 minutes everyday or every few days (as opposed to spreading out fewer terms over, say, two weeks). The conjecture I have is that my brain commits to memory more heavily based on frequency/intensity during short intervals of time rather than long intervals of time, but it's just a guess.

Not sure if I'm just an outlier, but I think you're right that many learning heuristics aren't one-size-fits-all. Hope you can find something that's effective (and enjoyable) for you. :)