Answer:
Oral tradition is extremely important to preserve in all societies because of many reasons. Not all societies rely on writing to preserve their knowledges - some prefer to transmit knowledge from one person to another through oral tradition, meaning - tales, fables, myths, proverbs, songs, etc.
In the past, oral tradition was all we had - it was a good way to bring a community closer, to teach younger generations valuable lessons, to preserve history of one nation. Even today it's an important tradition - parents read bedtime stories to their kids, sing lullabies, talk about the past with them, etc. There is important wisdom in oral tradition and it shouldn't be abolished for the sake of written tradition.