I even have a thread about it
TL;DR: Even knowing 90% of the kanji here, it felt worth it to subscribe.
As mentioned above, the vocab here has been selected to reinforce specific kanji readings. That lead to many a thread complaining that the vocab on WK isn’t useful. And to be fair, things like 友人 or 寛ぐ are frequent enough in the wild, but probably not something to focus on as a beginner. Plus, there’s obviously no kana only words.
Long story short: you will need to learn vocab outside WK no matter what.