> Otoh, certain stuff that are not particularly important need frequent repetition, eg learning a foreign language that you are not actively using.
In that use case, you are much better off reading content in that language and watching content in that language. Vocabulary memorization as isolated activity makes sense only as additional activity if you have additional time on top of that.
I mainly use anki with cards that involve the vocab in some context. I found that the context enabled me to eventually understand without translating to any other language, I am still quite limited though. I think that falls into your suggestion of learning within some kind of broader context, which I agree.
In that use case, you are much better off reading content in that language and watching content in that language. Vocabulary memorization as isolated activity makes sense only as additional activity if you have additional time on top of that.