>>52498541. Kanji makes things infinitely more readable. Take 昨日は彼が駅で電車に乗りました. Just ignoring the actual kanji meanings for a moment, you can pretty quickly tell which parts of the sentence are nouns/vocab and which are pure grammar things. As opposed to かれがえきででんしゃにのりました which is gibberish. Also Japanese has many homophones which can only be differentiated by their kanji
2. Once you know a few kanji you can very easily guess the meaning of compound kanji. Take the kanji 学. You may not know exactly what 学校、学生、留学する、and 学ぶ mean, but if you know that 学 roughly means "learning" then you can guess that all those things have something to do with learning (they mean "school," "student," "to study overseas," and "to learn," respectively)
Think of it like how we use Latin/Greek roots in English. Except if we wrote them upside down in the runic alphabet
