Will it be worth it or not highly depends on your advantages and shortages in learning. But compared to other resources WaniKani has some mechanics, that works better.
I learned Japanese in class, where we study speaking a lot, but reading text wasn’t a priority. And also I’m watching a lot of anime with subtitles. So, listening is not a problem for me, and speaking is OK. I have a lack of reading knowledge, and electronic resources are really good to make it better.
I have tried Anki, but, because there is no need to print answer be yourself, it is quite simple to abuse it, even unintentionally. As a result, kanjis can be forgotten fast. Think Anki is good for repeating, but not so good at learning.
Also tried some other services, where user should type the answer by himself, but that always was sooo, repetitive, and with so many unnecessary parts. I don’t think that I want to recognise words by listening (at least for now) and recall kanji by kana (it’s not make sense for me). Compared to these, WaniKani has just that parts, what I need, I can done lessons fast, and recalling kanjis at good rate.
WaniKani also has a few disadvantages for my taste, but they can be easily avoided.
I don’t like all these radicals, that not really a radicals. And that names often isn’t the same as wide-known, so I have added a synonyms.
Think, I would prefer to learn “a radical + few kanji + few words with these kanji, repeat”, rather than “radicals, kanjis, words, repeat”. But WaniKani’s way is OK too. May be it is better at something, but I don’t know it yet.