Ballet flats really are a category of footwear which have been influenced from the shoes that ballet dancers wear. They are simply footwear that are minimalist in style much like the ballet shoes and have no design characteristics that do anything greater than cover the feet. They do not have a raised high heel and they don't have any support features in the mid-foot (arch). The minimalist structure additionally implies that they have to fit the feet snugly to remain on the feet. The design will mean that they don't affect the way the feet moves or develops. You'll find nothing inherently incorrect with these types of shoes and they are generally sought after.
What happens if you do require some kind of mid-foot (arch) support? There are various clinical problems in the feet in which some type of arch support beneath the foot is called for. Quite often that is only needed in the short term and other instances it may be a longer term requirement. The types of conditions that may benefit from footwear with more support inside them could possibly be something such as fatigue in the legs and feet, particularly in those who find themselves standing on their feet for hours on end at work on hard surfaces. There may be soreness in the arch of the foot with disorders like heel spurs or disorders of the tendons, for instance posterior tibial tendon dysfunction. Often, individuals would rather use shoes with some kind of arch area support since they just feel much more comfortable using them.
What happens if you like using ballet flats and need some arch support? The main option is to stop using the type of shoes and use other designs that do involve some mid-foot (arch) support included in the shoe. This could only be a short-term change and you could get back to the ballet flats eventually. Foot supports are maybe the best way to address alignment problems of the foot and use them if you want support. The drawback with ballet flats is always that there's no space in the tightly fitting shoes to fit the foot orthotics within. The bespoke types of foot orthoses can be cut down to remove a great deal of volume and might manage to squeeze in these shoes when not very restricted. You can find sticky pads such as instant arches that might be glued inside the ballet flats to offer some arch support. These isn't going to be as good as a full foot support but they are a compromise that may help. In the event the problem is fairly minor, the use of these instant arches to provide arch support in the ballet flats may well be enough. However, when the biomechanical concern that really needs this support is more excessive the compromise most likely is not as helpful.
At the end of the day, if you wish to keep using the ballet flats and require arch support, you will be only getting this if you are able to sacrifice. You also might have to maybe alter your shoes to a different variety within the short to medium term if you need to get over the situation that you have.