For programming, memorisation doesn't matter that much. Not knowing the argument order for a function isn't a big deal. You use an IDE or you get a good offline docs viewer (Dash, DevDocs etc.) or you learn to Google efficiently.
Language learning is an obvious use case.
Also: law and medicine. Having knowledge mentally 'to hand' is pretty important if you've got a patient under general anaesthetic, or a judge asking you a very difficult question.
Memorizing word pairs can certainly be done with spaced repetition, but it’s unclear how much that translates to actual language ability. Second-language acquisition appears to be primarily dependent on reading (or listening to) the target language for content, and most words are learned via seeing them in context instead of being looked up in a dictionary.
I have no experience with law or medicine, but I expect the story is similar: practical knowledge is what you need to hand, and not book knowledge. Book knowledge is what gets you through the exams and into the practical part of your training.
Beyond the very basics necessary to extract some meaning from a second language, I’d be shocked if time invested in spaced-repetition drills of any design had better returns than reading the target language for pleasure.
Language learning is an obvious use case.
Also: law and medicine. Having knowledge mentally 'to hand' is pretty important if you've got a patient under general anaesthetic, or a judge asking you a very difficult question.