In my experience, students of all ages need help to stay focused. In theory, annotation helps them pay attention while reading. The act of commenting and questioning enables a closer read so it also helps students understand the ideas in the text. Having students reflect on ideas they are reading about gives them a low-stake, organic boost to participate in coursework later. If done right, I notice the effects in class discussion, roundtables, written works, and exams.
https://eductive.ca/en/resource/real-life-story/boosting-engagement-with-social-annotation/