No, it is not compulsory to paraphrase the question. You just need to address the task. That’s all. The given essay should get band 8 to . These are approximate values. The IELTS essay task tests your ability to express your ideas coherently. Grammar is an important thing to consider. So is your vocabulary. Grammar mistakes will bring your score down. So, the examiner is more interested in evaluating your ability to express your ideas in grammatically correct English. They aren’t trying to assess your ability to paraphrase. By the way, who said the student hasn’t paraphrased the question in this essay? All the ideas mentioned in the question are included in the first paragraph of the essay. That is enough.