Because the prophet pbuh commanded as to make a general practice of wearing sandals. Many people have wider than normal feet. They get normal shoes, whereas they need wide foot shoes. Get two pairs because everything important must be bought and kept in pairs.
One for use and one for backup. And not just shoes, but every piece of essential equipment should be kept in pairs. We ask Allah to forgive us and to give us the best. Shoes always ameen.
Islamic Principles Website 