Due to the immense success of the film Willy Wonka & the Chocolate Factory, a sequel might appear to have been an obvious choice. However, there is one particular obstacle that prevented its production. British author, Roald Daul, has been aptly dubbed one of the greatest storytellers of the 20th century, and he is responsible for the creation of many children's hits, including The BFG, Matilda, and Charlie and the Chocolate Factory. Many of his books have received the adaptation treatment, including Charlie and the Chocolate Factory.

https://screenrant.com/willy-wonka-sequel-glass-elevator-dahl-canceled/