The following is my Baidu answer, which I think makes sense.

This is a big word, isn't it? You are so careful.

This is normal.

Japan and Korea were once vassals of China.

Until World War II, Chinese characters were widely used. ...

For example, Japanese Hiragana and Katakana are all born out of radicals or parts of Chinese characters, while Korean Chinese characters are mostly born out of China's cursive script.

However, after World War II, in order to better control Japan and South Korea, contain China, and force them to increase the use of their own characters and reduce the proportion of Chinese characters in Japanese and Korean daily language, it became like this. ...

But in fact, the upper classes in both countries are proud of being able to write Chinese characters. Compared with, for example, in very formal places, the names on business cards are written in Chinese characters, and so is Japan. ...