In key stage 3/4, does your child do extended writing for English Language homework and, if so, does the work get marked by their teachers?
Our school only does extended writing in class, and either the students peer-review it, or else sometimes the teacher looks at their books. I always assumed this was so that the teachers didn't have a lot of marking to do. More recently, I was told it's because if they did writing for homework many students would use AI (though the English department was doing it this way long before ChatGPT was launched).
The teachers obviously do mark their summative assessments. My eldest DC always got 8s/9s in those, so I wasn't worried, but in the actual GCSE he got a 6. We got his paper and I was a little shocked by some of his grammar and spelling. It made me regret not seeing more of his work at home over the years because I would have intervened if I'd realised.