Although you can do direct transfers now p to p. Decentralised exchanges are coming. They will take us back closer to the original vision Satoshi Nakamoto and the cyber punks . We currently use centralised exchanges because they are more efficient than finding someone to exchange with . It was not always so . There was a time when if you wanted to buy coin you advertised then met the individual who had it to do the exchange . The eventual arrival of decentralised exchanges will cause an exisistential crisis for the exchanges now operating.
ps://media.consensys.net/state-of-decentralized-exchanges-2018-276dad340c79
