Writing is not that necessary of a skill in Japanese- even many native Japanese speakers no longer remember how to write many characters.

There's even a self-deprecating slang term: https://en.m.wiktionary.org/wiki/%E3%83%AF%E3%83%BC%E3%83%97...

"Writing" here probably doesn't refer to writing things by hand with a pen, but rather the act of composing emails, text messages, essays and so on.

Even just forgetting about Kanji for a moment, just like in other languages, written Japanese is not identical to spoken Japanese and requires practice if you want to be able to compose natural sounding texts, emails, letters, and so on.