Earlier quoted context omitted.
Being fluent in Japanese as a second language, I agree with this. It's Zipf's law and sounds great, but 90% isn't as useful as it sounds. You'll mostly recognize a single common Kanji of compound words consisting of 2-3 characters, or common structural words. It's a far cry from being able to understand content you find in the wild. Also, "understanding" a Kanji is an ill-defined term. Most Kanji have multiple meanin…
Afterthought: Kawaii (cute) is actually 可愛い, also containing "可", which literally may mean something like "a thing that can be easily loved", or simpler, cute. But you wouldn't be able to guess that if you just know the Kanji.
You obviously learn it by itself but as Chinese words are mostly a combination of 2 characters, you immediately also have to learn e.g. 可以 (can, may, be able to), 可能 (maybe), 可爱 (cute) etc.
So someone who's learning characters in order to get 90% coverage (or whatever) would not simply learn characters but learn actual words. Learning characters in isolation would not be that helpful, indeed.
When you don't know a word (i.e. a combination) but you know the individual characters it is much easier to learn the new word either by guessing or checking.
In context, the meaning of 可爱 would be fairly straightforward to guess, for example. Even in English 'lovable' is a synonym of 'cute'.