Good writing skills essential: Research of any kind (this ends up being a vast category & covers any field of study, including the most mathematical & scientific), teaching, law, social work, advertising, publishing & editing, campaigning, politics, webpage & content construction, archivists, middle & higher levels of management in any large business, large institution and local government admin.
There is, or perhaps was, a brickie who writes articles for the Telegraph. So even builders don't escape the value of good writing. Childcarers have to keep lots of written records & up to date written policies: just loads of occupations where good writing is very helpful if not essential.
I feel the same about maths, by the way, no idea how people get a "good" job without good numeracy skills.
Agree that people (kids) can be excellent writers without meeting highest NC guidelines, though.