I think the biggest disadvantage of bitcoin is its whole idea of anonymity where you can pay someone without even knowing or tracking them thats why there are so many scam sites this days. But im not really against it I even like the idea of investing and earning without giving my real information

happy earning guys
I think this not a main reason here the disadvantage that i know is the speed of the transaction and like other said anonymity because of illegal activity but i think it is not the case because illegal activities are still happen even in other currency or fiat..