since they are not technically magical, they only count as magical for the purposes of overcoming resistances and immunities, there are certain edge cases where this feature will be more or less useful than a normal magic weapon. For instance if fighting an monster immune to bludgeoning, piercing and slashing damage from nonmagical attacks inside of an anti magic field becuase you have a cruel DM, your ki-infused kicks and punches can still damage them normally, and if wizards of the coast ever made an monster that was so resistant to magic or that fed on magic that they decided to give the monster resistance to bludgeoning, piercing and slashing damage from magical attacks, your attacks still would overcome that because they aint magical. And if they did the opposite, made an monster that was vulnerable to bludgeoning, piercing and slashing damage from magical attacks the attacks of the monk would not be able to deal double damage with their fists because the attacks are not magical. All of these scenarios probably will not happen but should they happen it is important to remember that your punches are not made of magic, rather they are infused with mystical ki energy that lets them overcome defenses in ways mundane strikes cannot