Disadvantage is the risk and volatility, the lack of notification and understanding, with incomplete functions, but which are developing, so Bitcoin is not perfect.
As my programmer friend always says, there is no perfect system, and neither is bitcoin. There are risks that need to be taken, there are a lot of things to consider and we should be aware that it is not always a profit. All in all, the biggest advantage and disadvantage of bitcoin is the fact that it is a volatile crypto currency.