Don’t worry too much about it. They use vocabulary to reinforce the readings of the kanji. I personally think some of the vocab I have learned isn’t “useful” in a practical sense. There will be lots of everyday words that don’t feature. Wanikani teaches you kanji. It’s not the only resource for Japanese vocabulary as a whole.
For vocab, I’m currently using the core 2000 decks on anki. There’s a lot of context sentences with audio in those decks, they’re good quality. It’s exciting when you hear a sentence and understand it completely.
https://ankiweb.net/shared/decks/core%202000
For grammar there’s www.bunpro.jp
For a complete list of resources, someone here created this awesome list.