Root comment states that language skills are required for teaching all subjects, and math is also fundamental to all subjects. Root comment is of the “unpopular opinion” (their words, I consider this phrase to be an emotional appeal when used in this context) that some basic skills are required of everyone in the teaching profession, regardless of the age or subject they teach, and that those basic skills include mathematics.
Thank you, I got that. Perhaps I should've explicitly added to my comment that my lack of understanding is about how school maths would help with, say, literature or arts teaching.