First of all, if all off-campus training institutions disappear, the impact on students will be very complicated. On the one hand, students may feel depressed because they like to learn new skills and knowledge after class. On the other hand, students may have more time and opportunities to participate in other activities, such as sports, art and community service.

Secondly, parents will also be affected. Many parents think that off-campus training institutions can help their children get better education and career prospects. If these institutions disappear, parents may feel confused and uneasy because they don't know how to provide better education and training opportunities for their children.

Finally, the whole society will be affected. Off-campus training institutions have become a huge industry, which has produced a large number of employment opportunities and economic benefits. If these institutions disappear, many people will lose their jobs, which will have a negative impact on the economy and employment of the whole society.

To sum up, the disappearance of off-campus training institutions will have a negative impact on students, parents and the whole society. We should try to solve the problems existing in off-campus training institutions instead of eliminating them. At the same time, the government should also strengthen the supervision of these institutions to ensure that they provide high-quality education and training services for students and parents.