People prefer Bitcoins over fiat simply because it gives them freedom any anonymity. It is flexible and convenient because it makes exchange of goods and services faster. Bitcoins along with other cryptocurrencies are also a way to escape taxes because it is decentralized. Hence no one, not even the government, can trace and track your transactions even if its illegal. This became a disadvantage for Bitcoin. It attracts illegal transactions and other bad works such as enjoying porn sites anonymously. Of course Bitcoins weren’t made for that.