While orthotics help to support the foot, children are the only ones whose foot can be improved with the use of foot orthotics because their growth plates are open and we have a chance to make some changes in the foot structure. Once someone reaches their 20s, the foot structure is already determined.
Use of orthotics will help raise and lift the arch while they are being worn and make the foot function much better and be more comfortable, they do not cause a lasting correction. This is similar to the way eyeglasses work, when you need a pair of glasses they will correct your vision while you wear them, but when you take them off, your vision is not improved.