I have had this tree for about 8 years and it has been grown in this wooden box for most of that time. I love how the branching of this tree twists and turns and how densely packed the buds are along the branches. It is just now beginning to leaf out and in a couple weeks most of the branching will disappear under a dense layer of green leaves closely stacked one on another as seen in the first photo. It's such a unique looking tree.
Growing trees in boxes reduces the rate of growth significantly and for a gardener with limited space and a love for trees that works pretty well. But it is not natural and it's a highly controlled environment that then requires many more steps and proceedures to keep it alive and healthy...that is to a degree. If this tree was in the ground where it's roots could function in the way they were designed to function this same tree would probably be 6-8 ft. tall after 8 years compared to the 3 ft. it has reached in this box.
People aren't any different. Box them in with a limited vision of what they have been created for and the same stunted growth will occur. Allow them the same freedom their Creator has given them and you might just be surprised what happens.