i think paper money will stay always and paper money are using in large number in everywhere and i also like paper money than coins .
you are right. paper money may still survive, and will always be used, because it is based on how it is used alone, paper money is still easier to use than the coins. but I am not sure that bitcoin someday be in shape in the form of coins, but probably bitcoin will be created in the form of a card, because credit cards can be used as an alternative payment. bitcoin might also like it