one (small) group that has taken to spaced repetition study techniques quite enthusiastically is the tournament scrabble community. the thing about scrabble is that you don't need to know what the words mean, you just need to memorise "acceptable sequences of letters", and also while there are ~275000 valid words in the official dictionary, people have already done the work to sort them into usefulness order. so if you want to play top-level tournament scrabble it is really helpful to simply memorise, say, the 5000-10000 (depending on your dedication) most useful words, keyed by "alphagram" (the alphabetically sorted set of letters in the word). e.g. ADEINRT -> [ANTIRED,DETRAIN,TRAINED]. again, you don't need to know or care what those words mean, just to know the they are the only three words made from that set of letters (as an aside the most useful words to memorise tend to be predominantly 2, 3, 7 and 8 letters long, most tournament players master the 2s as soon as possible, take a while with the 3s and start "cardboxing", scrabble jargon for using a flashcard app with spaced repetition, to learn the top few thousand 7s and 8s)

anki itself is not super popular since there are apps like zyzzyva that are specialised for scrabble word study, but the technique is.