There is a commonly held belief in foot care that flat feet must be supported. But it’s unclear what exactly the definition of a flat foot is, and what complications it leads to. Arch support in traditional footwear does not teach you how to use your feet well and it doesn’t allow you to use your foot muscles, so it might actually hinder rather than help. Foot function is a much bigger indicator of success than the height of your arch. As long as there is no pain, dysfunction, or underlying pathologies, then both kids and adults can wear barefoot shoes even with flat feet.
Read this article for more on why arch support isn’t a long term solution + related research articles.