Decentralized Exchanges follows the idea of blockchain, that is to say, in decentralized exchanges, users are still in charge of their wallet as all trades occurs within their wallet. Because of this, hacking a decentralized exchange has proven to be hard, as you will need the users keys to perform such which isn't possible. So in all, Decentralized exchanges offers high security, transparency and trust. Also, there is no need for KYC..