Writing and editing are both useful and important skills. Better students at every level from high school up quickly learn the value of having someone else turn an attentive and critical eye to their work, before a final version is produced.
Schools should consider assigning essays, then requiring students to submit their original drafts, editorial remarks from an assigned classmate, and the final version. Each student would then get graded on both their final essays and the quality of their editorial comments. A sensible balance might be 2/3 for their essay and 1/3 for their comments.
It would definitely be more work to grade, but I think it would be a worthwhile thing to do from time to time. In a great many professions, the ability to give and receive constructive criticism is an essential skill. People should start learning it while they are still in an academic environment.