If you are a high school student, your study goal is to get excellent grades, and you find that you are not good at certain subjects or knowledge points, then attending targeted extracurricular remedial classes can provide more opportunities and resources to help you better master the subject content and skills.
If you want to apply for a foreign university or a high-level university and need to get high marks, then taking part in extra-curricular classes of some famous schools or majors can enhance your competitiveness and give you a better chance to be admitted to top schools.
However, it should also be noted that taking part in extracurricular classes also requires time, energy and economic costs. If you have done enough review and practice in school teaching and can learn and master relevant knowledge independently, it may not be necessary to take part in extracurricular classes.
In short, whether to participate in extracurricular classes in senior high schools needs specific analysis, and it should be decided according to one's actual situation and needs. The most important thing is to maintain a good attitude and method of learning if you want to achieve ideal academic results in high school.