you just said it yourself.. the leaves are what creates the food and sugars for a plant via photosynthesis.. take away the leaves, you take away the plants ability to create foods and sugars..
when you remove leaves from a plant to allow more light to get to the bottom of the plant, just where exactly if not the leaves are you trying to get the light too?? serious question..
buds only have a small fraction of the chlorophyl in them that leaves have, therefore the leaves grow the buds, not vice versa..