While pleats in smaller sizes like S, M make the customer wearing the clothes look better, the pleats should be reduced to the extent possible for larger sized clothes of size 3XL, 4XL.
The women purchasing these clothes are looking for clothes which will make them look slimmer, especially if they are short.
Additionally, the clothes seller can also reduce the manufacturing cost of the clothes, if they use less fabric for the clothes, reducing the pleats in the clothes.
The photos are not very accurate, only when the customer receives the clothes, they realize that the clothes are making them look fattter and rarely wear these clothes because of their design.