I've never used Bancor... but just DEX's like IDEX and EtherDelta. In my opinion, they're not nearly as user friendly as centralized exchanges... but I do like the fact that I still have ownership of all my coins and I don't have to worry about an exchange getting hacked or stealing coins.
Binance is going to launch their decentralized exchange in the upcoming year so it maybe a turnaround in the centralized exchange then people will trust more on the exchange and will keep their coins into theor wallets.So yes the future will be decentralized that is why satoshi nakamoto found decentralized crypto currency.