Why do Buddhists not rely on material goods to make them happy or fulfilld?

According to Buddhist teachings, material items have a temporary effect on one's mind and do not offer everlasting happiness. Instead, Buddhists believe that inner happiness and fulfillment come from non-physical practices like understanding oneself, developing wisdom, and practicing mindfulness, compassion, and love toward all beings. They teach that true happiness can be found when one lets go of material possessions and cultivates internal harmony and contentment, which ultimately transcend transient material pleasures. Material abundance alone is not considered sufficient or reliable for attaining a profound sense of fulfillment in life.