Speaking in English builds confidence in a child which can set him on the right path to express and present their ideaswith nothing holding them back.
Strong English skills can develop important life skills in kids, such as effective communication, expression, opinions etc. Better English can inculcate a habit of reading in English, which prepares them for their future beyond the classroom.
There are manywell-established competitive platforms like Spell-Bee, Logiquiz, Olympiads etc. which mainly conduct their quizzes in English. With essential knowledge of English, a kid can participate on these platforms and prove their mettle.