I think there is a reason why we all do this.
1. Lack of English courses in schools
For example, according to the syllabus, English courses in primary schools do not teach phonetic symbols, but teach children words directly. I don't understand the scientific principles, but there are indeed training classes on the market to teach children phonetic symbols and spelling. The training class is still good at grasping business opportunities, and some parents must think that phonetic learning is necessary.
2. School education is taught in large classes, and children rarely get attention.
To put it bluntly, it is the difference between a big pot of rice and a small stove. There are 30-50 students in a class, and a class lasts about 40 minutes. In order to complete the teaching progress, the content of each class must be arranged compactly. If every student speaks in class, even if one person speaks, the teaching progress may be difficult to complete. In order to be in a hurry, teachers are used to asking questions to students who answer quickly. On the one hand, they save time, on the other hand, they want such children to give the whole class a correct demonstration. This virtually makes students with poor English lose the opportunity to exercise.
I want to add here that parents should not be angry about this and say that teachers are biased. In fact, if you were a teacher, you would do the same. Some students are really speechless when they often stand up when asked questions, or falter, answer irrelevant questions, their voices are very small, or they often answer irrelevant questions, or their pronunciation is not standard. The consequence of teachers asking students this way is to delay valuable classroom time and even attract the whole class to burst into laughter.
Therefore, in order to take care of the overall situation, teachers will try to reduce questions from students who are not good at English, and in order to take care of these students, teachers will give them some relatively simple questions. Indeed, there are so many people in a class that teachers can't take care of every class. This has also caused students to learn English at school and have insufficient exercise.
As a result, parents of students with poor English reported English training classes to their children. Parents of students with good English also feel that school study time is still not enough. These parents tend to pay more attention to their children's learning, so they are still signing up for training classes.