Apical dominance is a correlative phenomenon in the developmental biology of plants. Branching of the main shoot into lateral branches is one of the main characteristics of the growth of most of the plants. More branches mean more leaves and more of photosynthesis. Branching also helps a tree to avoid crowding of leaves. Branches provide an opportunity for exposure of maximum number of leaves to sunlight. Branching has a distinct evolutionary advantage, as it helps a plant to survive in a variety of habitats.
A plant that does not branch finds it difficult to survive in crowded forests or in areas where the light intensity is low. If you go around your place of stay or your place of work and start observing the big trees (flowering plants), you will come across two different types of tree growth. One, "monopodial" where the main bunk grows tall-bearing a crown of leaves at the top without much of lateral branches such as the large majority of palms and the other- "sympodial" where lateral branches start spreading out leaving a gap from the apex. Plants which exhibit the second type of growth pattern are quite useful as they provide lot of shade from hot sunlight apart from providing economic benefits like timber and fruits. Plants with a monopodial growth habit find it difficult to survive in temperate forests where light availability is poor. Palms mostly grow in tropical regions. Interestingly, bamboos have underground stems (rhizomes) like grasses which show both monopodial and sympodial branching pattern.