When learning new vocab (I’m currently in a real vocab hole and apparently have to learn 450 (!!!) new words before Wanikani will give me any new kanji) I rarely even look at the context sentences as they nearly always include kanji that I don’t know.
Ideally they would only show me things I know how to read, but failing that furigana readings would be very useful. I guess this is a big ask, but it would certainly be useful.
As they stands they’re pointless, and rather demoralising.