Yes. Over 12 years of use I have consistently found spaced repetition to be the most enjoyable way to learn basically anything, and essentially the only way to ensure things I don't regularly use as part of my job continue to be things I can remember. Some subjects I have in rotation at the moment: Finnish, Haskell, SQLite database internally, cash management and financial jargon, old photos and video clips of my childhood cat who I loved dearly.

But, more to the point: You seem confused as to the true generality of the technique. Flashcards can be used in much more interesting ways than just checking to see if you can recite all the lines of Homer correctly or something.

The vast majority of cards I have are questions of understanding - e.g. a card like "How many unique strands of DNA can be made from 100 A-T pairs and 100 C-G pairs?" You can't memorize all those digits. You need to remember how to solve the problem, which is quite simple, but not so simple it's worthless for a non-mathematician to solve without pen and paper.