Parents do it themselves.
Parents are the best teachers for children to learn languages, so the task of tutoring children at an early stage naturally falls on their shoulders.
A good foundation for learning English
Even if there is only a little level, as long as it is taught to children, it will lay a good foundation for learning English and make a good start for learning English in the future.
Children are highly flexible in using language.
Children's flexible use of language is unimaginable for adults. Adults may not be able to express themselves freely when they master hundreds of words or phrases, but it is possible for children to finish.
Modernization of teaching equipment
Nowadays, the teaching equipment has been modernized, and various teaching AIDS abound. Simple operation can get twice the result with half the effort.